I've recently had to go on (for a few months) some medication which had the side effect of significant cognitive impairment. Let's hand-wavingly equate this side effect to shaving thirty points off my IQ. That's what it felt like from the inside.

While on the medication, I constantly felt the need to idiot-proof my own life, to protect myself from the mistakes that my future self would certainly make. My ability to just trust myself to make good decisions in the future was removed.

This had far more ramifications than I can go into in a brief comment, but I can generalize by saying that I was forced to plan more carefully, to slow down, to double-check my work. Unable to think as deeply into problems in a freewheeling cognitive fashion, I was forced to break them down carefully on paper and understand that anything I didn't write down would be forgotten.

Basically what I'm trying to say is that being stupider probably forced me to be more rational.

When I went off the medication, I felt my old self waking up again, the size of concepts I could manipulate growing until I could once again comprehend and work on programs I had written before starting the drugs in the first place. I could follow long chains of verbal argument and concoct my own. And ... I pretty much immediately went back to my old problem solving habits of relying on big leaps in insight. Which I don't really blame myself for, because that's sort of what brains are for.

I don't know what the balance is. I don't know how and when to rein in the self-defeating aspects of intelligence. I probably made fewer mistakes when I was dumber but I also did less things period.