I’m a Web Developer and i’m loving it. Yet, Disappointed.

Long Story Short.

I have started as a Developer like a year ago and i'm able to solve most of the issues quickly. But some issues where i get stuck which seems to very simple to my leads and when they provide me the solution for it i feel bad for not thinking in their way. How do i have to think or change my thinking when i get stuck with an issue?

Any Advice is much Appreciated!!