I am not a qualified shrink, but it occurs to me (duh) that Michael had a seriously depressive personality.

If you look at the arc of his life, Michael is ALWAYS in a negative frame of mind. In the flashback scene, Sonny introduces him as that "droopy" thing over there. Michael is not particularly happy or proud that he signed up for the Marines, but instead seems defiant and angry --- as if he did it to piss off his family.

As he goes through his whole rebellious stage telling his father he will never be a man like him, he is also not a happy young man. Then when he takes over the family he seems to resent his role as having been unjustly put on his shoulders.

I cant think of any scene where Michael is actually enjoying himself. Sonny certainly knew how to have fun, so did Fredo, Tom did to a lesser extent, and even Vito could enjoy things like the love of his family, a nice piece of fruit, a glass of wine, playing with his grandson...but Michael..no way.

I wonder if Michael didnt carry around such depression and anger if he would not have been a better Don and maybe not as trigger happy and perhaps more able to make compromises, and live less dangerously (like Vito).

Anyone have any thoughts on this?