This is a common trap for intelligent people. Because of years of everything being easy you have that expectation for every situation. You never learn how to challenge yourself. Additionally your identity and social status was built on always being capable and smarter than others around you.
When suddenly you run into something that actually takes study and dedication, you just don't know how. Studying and persistence are learned skills. It's also embarrassing and causes you to shy away. Things seem impossible if you have no experience of being challenged. Depression and avoidance takes over.
Before you know it you're middle aged and never did any of the amazing things that everyone expected of you as a child prodigy. Potential was capped at the level that requires no effort.