Anecdote: Not directly relevant, since we had different goals, but... I had the same realization, at around age 28. Had a BS (both meanings) undergrad degree i

Anecdote: Not directly relevant, since we had different goals, but... I had the same realization, at around age 28. Had a BS (both meanings) undergrad degree in applied science. Path: -Math fundamentals on Khan Academy. Videos, exercises etc. Algebra, trig, calc etc -A barrage of science classes for a few years on MitX, only after I was comfortable with the math. Physics, chem, bio, biochem, QM etc Lectures, excercises etc. - Got more aggressive with personal projects applying these. Ie transition from learning fundamentals, to applying them to practical problems. It's not too late! It gets harder with age. EO Wilson (famous biologist and ant expert) described taking calculus for the first time in his mid 30s, and having a struggle.