I also think it takes 4 to 5 years to build a good set of "bike legs." I've noticed that it doesn't take me near as long to get up to speed in the spring than it did the first 2 to 3 years of riding and I'm just as active or less active in the winter.

And one rule I learned the hard way: Never, ever, take off on your bike without food and water no matter how far you are going.

While on a camping/bike trip in Wisconsin one year the group decided at dinner to eat breakfast the next morning at a local restaurant in town before hitting the road for the day so DH and I woke up, packed up our tent and headed out with the group only to pass the restaurant on our way out of town. When we spoke up we learned that some folks in the group had decided we would ride to the next town (30 miles away) and have breakfast there. They had forgotten to tell us. Besides being really po'd, we rode the next 30 miles on a stale, half-eaten Clif bar we split between the two of us. I have never gotten on the bike without food since.