Writing a regex involves always looking up the syntax, and being unable to read it an hour later without having to carefully disect it. I say this with 20+ YOE and I think I am better than the average bear with them.
That said, knowing what they can do is important and very useful. Its just the implementation that never quite sticks.
No. I mean, I believe it does for you. I use it often enough that it's always fresh. On the other hand, I always need to look up the syntax of CREATE TABLE. My experience can be described the same as yours.