For example, when you get dumped by a loved one, you'll often question yourself for a long time about what happened that caused the failure. Sometimes when you really want answers, you'll tend to avoid noise and people. This is what I call "hermitting". This behaviour can get compared to that of a hermit, because the person rather spend time alone, to think, than with people having fun and socializing.
Sometimes, after a major turn in life, hermitting can be a necessary phase of "digestion of events" before being able to move on.