Unexpected circuit breaker tripping

We had an unexpected circuit breaker tripping last night. For some reason, I could not reset the breaker from the service panel.

First, I suspected that it may be fault of the GFCI outlet, since it can't be reset. Actually I didn't know that the GFCI can't be reset when there's no power supply or it's not correctly wired. So I went to Home Depot and purchased a new GFCI outlet, and replaced the one at my bathroom. Still I can't reset the tripped circuit breaker. Frustrated, I went to bed, and I thought that I had to look for a licensed electrician tomorrow.

Early in the morning, I called my neighbor, he suggested that I should turn the tripped breaker all the way down, then reset it back. I followed the instructions and it worked.

Here's the lessons learned:

1) for a 15A circuit breaker, should not overload it.

2) when tripped, know the right way to reset it.