@Aristoddler,
It sounds to me the scenario addressed in the OP is the opposite of that of a mid-life crisis. A mid-life crises arises, as others have said on this thread, out of a recognition of finitude and manifests itself in desperate attempts to realise the dreams we gave up on and fool ourselves into believing we are younger than we are and so have more time. At 37, running out of time doesn't seem the likely problem. More likely imo is that the fellow in question used to live a certain lifestyle, gave it up to accept some responsibilities, has done so for quite a time but realises that he has a long life ahead of him yet and can't accept the idea of living this current lifestyle for another 30 years. In other words, the problem is one of too much time, not too little. I've seen this many times in younger people who have worked a job or had a career for about 10 years.
The expectations we have of ourselves are not our own, but are inherited, forced upon us. Some people think they should live a certain way (the usual way) and have to fight against their desires their whole lives. I have to admit, partying is not a very high ambition but I guess to the man in question it is the acme of living life to the full.