Indeed, many people cross forward and backward between the two.

I have a mathematics PhD and have worked in academic research, industrial mathematics and software development. I agree with Princess_Stargirl that mathematics and programming feel quite similar, but for me mathematics is less relaxing because it's harder. Yes, it's great when you "have an argument that works and isn't insanely complicated", but until you get one you don't even know that it exists. Which is stressful if your pay, or reputation, or career prospects, happen to be governed by your success in finding such things.

(Whether, and how far, the same is true in programming depends on exactly how you define "programming". If you take it to mean the whole process of going from nothing at all to high-quality software, then it does share that characteristic with mathematics. But the very researchy open-ended work is a smaller fraction of programming than of mathematics, and there are people happily and productively employed as programmers who do scarcely any of it at all.)

I would expect that you could probably practice on a targets that won't call the cops on you first (you could try reaching into large jacket pockets or purses and removing appropriate objects to make sure you don't jostle them). I am not a thief, have never pick-pocketed anyone and this was just the first idea that popped into my head.

No, you practice first. For instance, when I was a magician and trying to do watch steals, I would wrap a towel around a broom handle, put the watch around that, and practice the motion over and over again before I tried to do it in the real world.

They have online dating now. Yuo can prety much do this at any time you can do programming.

I'm an economist not a programmer, but shouldn't the goal of programming be to write code that other people value? Also, you do need other people to program, the people who build the hardware, operate the power system, grow your food..., it's just that with extremely high probability you can count on them being there for you.

It does if you interpret James's comment to mean interactions with romantic intent.

Dating a single person for a long time is akin to managing a team of developers (sure, you don't get quick feedback) and chatting to someone you don't know in a book store is like quickly compiling something in a new language.

In electronics, one designs a system from smaller components to fulfill a particular function

This is true, and this is a similarity between programming and electronic design. However, this is true of a great many other things too - automobile design, architecture, industrial engineering and manufacturing, design of ships, tanks and aircraft, etc. Are all of these things "basically still programming"?

You can switch to buying your groceries at a farmers market where you can negotiate price.

I also know someone who brought a bunch of WoW Gold on ebay and then practiced buying and selling WoW items to practice his sales skills.

Checked it again, this sentence is still there:

"I mean this in the sense of "activities that also satisfy the above criteria", but suggestions don't have to satisfy ALL of the criteria. Here are some of the first ideas that come to mind when I try to answer the question myself:"

Most of those criteria are extremely subjective - For instance, many people would say that programming needs expensive equipment, a specific location, and is nerdy instead of badass.

Similarly, all of the subjects above can fit all the criteria when you know what you're doing, how to practice them and how to use them.

LOL. Not that this was an entirely serious suggestion, but what expensive equipment do you need? Why do you need special credentials or a school? Why any mistake automatically leads to death?

Music is like the art of math. The playing of musical instruments is art, but the writing of it and the instrument design and the understanding of how those instruments operate is all math. Music can be created without art, but music cannot be created without math; not even in the slightest aspect of it. It is the only major form of classical arts to which that claim can be prescribed. A drum requires a calculation to generate reverberation to make itself heard. A scale must be calculated from its underlying frequencies. Strings must be measured in length, thickness, and tension to determine their resonance. The hole spacing and size of wind instruments must be calculated. Even something as simple as humming while alternating between high and low is a binary expression of either volume or frequency. It is only over the course of several millennia that we have developed the ability to teach an artistically gifted person to generate music without learning a bit of math. But that person still owes their artistic creations to the mathematicians of history. The connection is not at all tenuous. It is a very clear case of cause and effect.

Whether it's simply a rhythm, or playing a melody, or adding a harmony, every part about playing music engages the math part of the brain.

That doesn't mean you need to understand calculus to play. It's simply addition and basic translations, but it's a constant barrage of adding things and subtracting things.

If it's a piano or guitar, or even a voice, you have to know that do re me fa, is whole step - whole step - half step. The fretboard or keyboard is a large numerical puzzle. It's right in front of you, and what makes a good singers is someone who mentally works in that musical puzzle. Adding steps and half steps. You never really add past 12, because you can start over then. You don't need an advanced mathematics degree to solve the puzzle, but your brain is doing (simple) math constantly.

Not only that, but music is, since the beginning of time, the essential example of how to train your brain, to do without doing. The brain patterns of jazz musicians in performance resemble those of meditating monks.

The idea that the connection is tenuous may suggest you don't play music. If you've never made a beat before, try this:

openmusicgallery.appspot.com/drums.htm

Now keep in mind, this is just telling the program when to play a beat. If a human were to try to play these beats, they'd be doing math the entire time (not differential equations, but still math). Making sure beats are evenly placed is just counting. Once you've done it enough, you don't literally need to count "1,2,3,4" but I know many professional drummers that do exactly this, and are nearly flawless because of it.

I'm a professional musician, I also do creative coding for artists. One interesting tension is that some artists don't think that music is art. I agree with them 99% of the time. You can get paid a few hundred bucks to play Lynryd Skynrd song, which ends up being paint by numbers.

Music on the whole is just paint by numbers. Occasionally it breaks into the realm of genuine art. In any case, like programming, I find that it is merely a vehicle for expressing things.

Playing in time, and in key are pretty objective. You want unforgiving, try to sing the Star Spangled Banner out of tune at some event.