I made it pretty deep into calculus in college but hadn't practiced much higher-level math since. Not long ago I was trying to do some VERY-basic pre-calc math for fun and could NOT figure it out. Something that would have taken me 30 seconds in high-school or college.
After re-learning it I got it again, but yeah it definitely wasn't instant.
After re-learning it I got it again, but yeah it definitely wasn't instant.