It's a Personal Problem
When I’m learning a new topic or subject, I tend to get frustrated quickly as I’m not able to pick up a [complex] subject within a few moments. I typically give up less than an hour in to studying. It normally takes me a few times stumbling at the subject before I really block our distractions, focus in, and realize I need to devote more time. I find others need to do the same.
I have find others give up too early or do not give enough thought toward learning. They believe they already have enough knowledge or know enough about the subject.
Take a step back. Ask yourself questions. Whiteboard some things, explain it to others. Write it down, make a blog post, give a speech about it at some local community group. This will help in bringing to light where your knowledge is lacking and gives you a chance to strengthen it all that much more.
Don’t be afraid though, plenty of others still don’t know what you do. Share it, they will be very appreciative of you.