Another Commuter here
I ride to work also - about 12 miles round trip and I've added a lunch ride of anywhere from 10-14 miles. I eat at my desk while still working and then take my "lunch hour" to ride. Then I ride on the weekends: either MTB or really long rides depending on time and mood!
Life should NOT be a journey to the grave with the intention of arriving safely in an attractive and well preserved body, but rather to skid in sideways, champagne in one hand, strawberries in the other, body thoroughly used up, totally worn out and screaming: "Yeah Baby! What a Ride!"