I have this compulsion to ride fast. If I'm on the bike want to go go go. The daily commute is likely the only exercise I'm going to get for the day, so I like press it pretty hard.

When headed out for a distance ride, sometimes it's difficult to slow down so can get to the end of a long haul. I does make a difference though. On days I'm feeling lazy, it seems to take about the same time, but I'm not thrashed when I get there.