Not being a coder myself this is a shot in the dark but it sounds like you are questioning yourself.....don't do that.

I would say move on and see what happens.  If you find out you missed something, you can always go back.  Have some faith and belief that you processed what you were taught.  I am sure it is somewhere within you.

We often do not know what we are capable of....at times, testing ourselves by just forging ahead makes us realize what was there.