A lot of this is probably going to sound incredibly unconvincing. I'd assert that I would have found it unconvincing had I not gone through it.
The first time around it was mostly a matter of me realizing that it was hopeless with this girl and that I have better things to do than worry. Not particularly vertebral, but sort of significant for me nonetheless.
The next time was a bit weirder -- there was someone who was a friend that I got a crush on, then we dated for a while, then split up, then at various times started dating again before I ultimately wound up in the friend zone. (I'd like to mention that she was pretty open about the whole non-interested not-seriousness of everything after the initial split, and it was more my pigheadedness that allowed it to continue). At various points during that, she would become somewhat interested in other guys.
After one incident (inviting one of said interests to a meeting with me), I had decided that I had enough of it and called her out on it. I then actually accepted that she wasn't interested, and had backbone enough to stop trying to accommodate her in every way possible. Following up, I became more secure in myself in general, more assertive and demanding of my own interests, and less worried about the opinions that other people don't actually have because they're not on average interested enough to judge you. So overall less of a pushover.
I'd have said that realizing in the first case that you were running your mind and your time was fairly vertebral. What am I missing?
Probably just curiosity at my end, but in the second case, did she turn out to be someone you wanted to spend time with at all?
We operate like this: the "overseer process" tells the brain, using blunt instruments like chemicals, that we need to find something to eat, somewhere to sleep or someone to mate with. Then the brain follows orders. Unfortunately the orders we receive from the "overseer" are often wrong, even though they were right in the ancestral environment. It seems the easiest way to improve humans isn't to augment their brains - it's to send them better orders, e.g. using drugs. Here's a list of fantasy brain-affecting drugs that I would find useful, even though they don't seem to do anything complicated except affecting "overseer" chemistry:
1) A drug against unrequited love, aka "infatuation" or 'limerence".
2) A drug that makes you become restless and want to exercise.
3) A drug that puts you in the state of random creativity that you normally experience just before falling asleep.
4) A drug that puts you in the optimal PUA "state".
5) A drug that boosts your feeling of curiosity. Must be great for doing math or science.
Anything else?