yeah we have in our training time standards on clearing, disassembly, reassembly, then functions check. the M4/M16 is easy i didnt touch one from 2004-2011 (2004 i went to basic the first time, didnt make it so they chaptered me out, and last year i was able to go back in the military after doing a bunch of stuff trying to get back in) and in that time i still remembered exactly how to disassemble and reassemble it.
"Without strife, the victory has no meaning. Without strife, one does not advance. Without strife, there is only stagnation."