I always wanted to keep a diary, but never had the time. I also don't like carrying loads of stuff around with me (apart from too many Mobile phones of course). I read recently that keeping a diary keeps you positive and upbeat as you can see what you've accomplished on that day, or at least remember the good times.
As both a realist and athiest I do sometimes find it difficult to be optimistic. I'm going to try to reflect this in my posts.