GrannyGear wrote my reply for me.
Especailly about the variety and the importance of family rides. However, I might add that I am lucky enough to ride every weekend one or both days with two guys who are very capable riders and we push along at about 18-19 or so and attack the hills. One of the guys is significantly faster, but he takes air out of his tires and takes longer pulls up front. We have a great time and work our butts off.
Today I rode 15 slow on my road bike. Then 12 more on MTBs with someone who doesn't get out that often. We found a country bar out in the sticks and stopped and had a beer!
Tyson