Complaining has it good points though:
You bring the problem out in the open where you can think about it more critically.
Sometimes when the problem is written down it doesn't seem so bad any more.
You can review your problems when you are feeling good, which makes it easier to find a solution (if there is one).
You will be able to cross things off on your "bad" list which will make you feel great.
You can think more clearly about any good things that came about as a result of the bad things (it does happen).

There is a long list of good things that can result from having a bad list, provided you don't get mired down in details.