I try to learn math but, after a while, I forget the concepts I don't use. That includes some parts of HS math, calculus, probability, analysis etc. I don't forget everything per se, I can recreate it easier once I read again (and I remember the basic stuff), but it's pissing me off how much effort I put in and it evaporates.

Am I retarded, /sci/? Probably, but is this something you deal with too?