I think understanding the why of mathematics makes all the difference between forgetting it soon after an exam, and being able to use it later in life.
I sometimes find myself needing to return to something I once knew in high-school / university to solve some problem, not being able to remember the specific methods, but the underlying bigger picture of the concepts comes back to me, and I can make progress from there.
I sometimes find myself needing to return to something I once knew in high-school / university to solve some problem, not being able to remember the specific methods, but the underlying bigger picture of the concepts comes back to me, and I can make progress from there.