[BeetleB]

> After having studied maths and physics at university and worked as a programmer in a mathematical field for 20 years (and studied much more maths in my spare time), I now see my poor recall as the limiting factor in my abilities in maths.

Same story here. Undergrad engineering math curriculum came easy to me, and it stuck as it was our bread and butter (calculus + diff eq). Once I got to grad level courses, the frequency with which we would utilize the material elsewhere dropped dramatically, and the net effect of that was I could never recall the topics until I needed them.

The next problem was even more significant: If I took even higher level courses, they relied on knowledge of the material I took in one of those prior courses that had not been burnt into memory, and may have taken 2+ years prior. The only reason I did poorly was because I had not memorized enough of the prior material.

On my own, I studied/reviewed the undergrad statistics course 3 times over many years and it never stuck. Finally, in 2018 I used spaced repetition to memorize much of the material, and over 3 years later I can still read material that utilizes those statistics and understand what I'm reading.

Memorizing is useful for things you don't use often.