Quitting my 9-to-5 to travel around SE Asia was the best move I ever made. Not only have I had countless irreplaceable experiences but my code has improved more in the last six months than in the previous five years combined.
My old job consisted mostly of maintaining and adding minor tweaks to mature codebases. Working on my own projects has given me a chance to do clean-slate architecture again. The things I've been working on (machine learning, DSP and OpenGL) are a lot more interesting and challenging than the corporate CRUD apps I was working on too. I have to be ruthlessly efficient with my time now that I can't count on a salary, so I've gotten a lot better at focusing on getting features done fast.
Travel itself is somewhat incidental to all this, but it's given me a tremendous incentive to make this experiment work because I want to keep traveling. Exposure to new cultures has also given me some ideas for new projects and given me a lot of aesthetic inspiration.
New experiences probably have some effect on your ability to think abstractly. I've heard similar anecdotes of people improving various skills due to traveling.
