I don't have a computer on the bike that I ride the most. And it's good that I don't. Some days I jam right along, some days I don't. But I know I am faster than last year, I am on my bike more this year than last year, and I'm being taken seriously as a "cyclist" by people at work and my own family.

I think sometimes the bike just doesn't want to go.
It's psychological.
Today I rode in to work, 25 miles, and because it was a Saturday, there was no traffic, no people, just me and the bike. And it took me ten minutes longer than it usually does.

I don't know why.

Think about this, though. Every ride is different. Sometimes, we tank up on water and maybe good food, and the combination of a good night's sleep and a tuned bike leads to a nice clip on the road. And sometimes, we wake up and we can't find our favorite shorts, and the dog won't come when called, and it's a little colder than yesterday, and our watch might be three minutes fast, and we might eat oatmeal instead of cheerios, and we might be a little dehydrated, and we might have ridden "too much" the day before, and man, it's just a drag getting on that hard little saddle and GAWD, didn't I JUST ride up that hill LAST NIGHT??? And the commute is not speedy nor is it particularly enjoyable. But it's still freakin' better than being in a car. I don't care what anyone says.

Stop thinking in terms of training.

Remember why you started doing this.
If you are like me, cycling saved your life.
So don't worry too much. Just love your bike. It's all you can do.