Hey....we've all done something like that. Don't be so hard on yourself. When I got my boat (new) back in 2006, I took my brother out to give her a whirl for the first time. Backing her in, I forgot one important detail. Didn't have him hold the bow rope!
So, as she traveled back off the trailer, all I could do was watch as she drifted out. Talk about feeling stupid! Anyway, another fisherman saw what was going on and came to the rescue. Talk about being embarrassed too! Like I say, we have lapses in judgment from time to time.