Poor Ralph doesn't have much luck with the ladies. Most of the ones he is attracted to either find him too immature or are put off by his constant stream of bad practical jokes and not-so-funny comedic routines.
When Ralph himself begins to believe that he is a loser, doomed to never finding the right girl and that his life and himself are pretty much useless, he decides to do the only thing which springs to mind and that is, of course, run off and join the marines!
A fairly good performance by Donny Most here. He doesn't get a lot of episodes with himself as the central character but overall, the episode isn't all that great. It has a poor plot and a weak script.