Don't be embarrassed! That is completely normal!
No really, it took me 10 months to understand the "For(" command too. In fact, my understanding went Repeat, While, and For(. This is because I found that Repeat could really do everything. Then I learnt what while did, which saved me massive bytes in my programs. The For( loop, however, I never understood…
It was actually this wiki that I read about the For( command 2 years ago. So I read it, and still didn't quite get it. What REALLY made me understand the For( loop was the practice I then did on it. I just kept using it in simple programs and saw what it does, and figured it out.
That's what I think you should do, just make simple programs designed to see what the For( loop does.
Cheers ~ James Kanjo