[snozolli]

I studied Spanish for years in school, then never really used it. Ten years later, I started studying Japanese. Whenever I got stuck, Spanish would come out. Spanish that I didn't even consciously remember. AFAIK, foreign languages are all stored in the same part of the brain, and once you warm up those neurons, they all get activated.

Not that it's in any way relevant to programming. I will say that after dropping programming for years, I can still explain a lot of specifics, and when I dive back in, it all floods right back. Personally, I'm convinced that any competent, experienced programmer could take a multi-year break, then come back and be right up to speed with the latest software stack in only slightly longer than the stack transition would have taken without a break.