I first seriously(?) learned how to code by finding a used Pascal book and reading it thoroughly. That was some time after getting my first computer and not knowing where to find a compiler! (I'm not counting forgotten Logo from summer class long ago or using elaborate triggers in a MUD.) I had serious learning problems getting far past that unguided. Finally learning C from some lecture notes was a growth spurt though I had looked at some C before that. Trying to calculate the fewest coins to add up to a sum and finding optimal new coin took like a couple weeks! LOL