Do you understand this: 1+1=2 ?
Most likely the answer is a clear yes.
Does this mean however that you understand mathematics, including advanced mathematics?
Our point is that what we think there is to learn is not necessarily what there indeed is to learn.
There is always more, lots more.
What you pay for is instant access to a knowledge that people like ourselves who have spent years of their lives refining their craft can give you in a very short period of time.