I often have trouble remembering to do things and then everything gets left, forgotten or cluttered.
Like the other month my home insurance lapsed and only after 10 days did I remember I needed to call, which I then had to do from my mobile which cost more, because I was on the way to see the Tour de France in Yorkshire, and knowing my luck, without home insurance the house wouldn't got set on fire or something.
Last year my car MOT ran out and the tax came up. No MOT, no Tax. So to sort it I had to drive to dads and then leave it on his drive for a month, when I had it sorted I had to cycle back to dads and get the car. Generally forgetting to do things or rushing things will end up with a much more effort filled outcome.
So for the past month I've been using Things by CulturedCode.com and they have released a nice little guide to help get you started.
My other reason for using things is its been helping to with make sure I've got everything in order for cycling and cyclocross training. Sometimes when everything is out of sync you just don't do what you intended and those big great ideas fall to nothing. Then the time runs out and then your floundering around in the middle of the race dying rather than nailing it at the front.