Is it normal for me to forget how to solve certain maths problems over time?

Eugen von Böhm-bawerk: Is it normal for me to forget how to solve certain maths problems over time?
I’ve noticed that over a certain period of time, I tend to forget how to solve certain maths problems and maths formulas? Is this normal? Do good mathematicians forget how to solve certain maths problems over time?

I ask because I want to be an economist, which requires a lot of maths. But now I’m highly worried.

Answers and Views:

Answer by gdr
quite normal. If you do not use the technique and do not practice them – then one tends to forget.
professional mathematicians use their math skills and techniques all the time so they do not tend to forget them, but the less used techniques may get a little rusty…