I guess it kinda depends on what you mean by 'a long time'.
Ya never know, you might be taking the average amount of time compared to others.

With learning leads etc.. I usually just let it come in it's own time.
It's like, you learn the lead as best you can, then wait and keep coming back to it. After awhile, your subconscious takes over and you don't have to think about it that much anymore. Kinda like learning to drive a car.

About the only thing I can suggest is to try and use your memory as much as possible. The more you use it, the easier it gets.