I've come to realize I don't push very hard on flat ground but I push harder on hills. I took a solo 20 mile ride today in the country where it is hilly. My commuting route is almost all flat. Today I got into a pace where in flat-ish places, I pushed harder. I see how it can be done. I'm not sure I want to on my commute, but I could do it. I'm lucky enough to have a MUP route to work in a city with horrific traffic. I can't complain about the bike and pedestrian traffic on my route, but I think the potential to go fast consistently is limited. Some do it, but they're either rattling people's nerves, or they're braking often. I don't like braking and then accelerating again.