I don't think there's a right or wrong when it comes to keeping track of computer stats. It's different for everyone. If you are competitively training to race, you certainly need to keep track more than the average cyclist. If you don't race, then it's more of a fun tool to use to see how you're improving, For me, getting faster and seeing the numbers on the computer is what MAKES it fun. When I go faster, I can keep up with certain people and do certain rides that I couldn't do in the past. When I see that I'm at a 16.4 average near the end of a ride, like last week, and it encourages me to push as hard as I can to the end to try to get to 17, this is a GOOD thing for me. I need any motivation I can get to make myself work harder, because I can be a wimp sometimes! (By the way, I got to 16.9 that day ... my fastest non-group ride ever.)

If keeping track of stats becomes an obsession and your only means of feeling good about your rides is based on what the computer says, then it makes total sense to leave the computer at home and go out and simply enjoy yourself. Right now I'm sort of in the honeymoon phase, where I'm new enough at this, that I am improving faster than someone who has been riding a long time and has maybe plateaued at a certain level, or over trained or gotten sick and weakened their fitness level. For me, the average pace number on my computer is consistently getting higher and this is hugely motivating for me to keep getting on the bike.