That's because you never actually use them, other than for interviews (sad but true). Happens to me too, I used to know many back at school, and now I can recal

That's because you never actually use them, other than for interviews (sad but true). Happens to me too, I used to know many back at school, and now I can recall just those that I use for work at least once in a 6 months or so. For everything else I usually remember some basics, but just barely enough to be able to quickly google what I need. And then you just refresh the memory when needed. It's like back in the days when hdd were expensive, so we all were zipping our files when not used to save space - and then you unpack them when you need them :)