Faster!

[Fredwina]

I would agree with yellow that you could just be hard on yourself.
as an example, The president of our club and his wife can do sub 5 hour centuries with no problems. I did a 'timed' century ride once. I wound up 4th, with a time of little over 7 hours. I was talking with him. The century came up and I asked him how I did. He acted dissapointed!
You can get Faster and better through training, but I think you have to remember that the only person you can really compete against is yourself.