Because I live nearby to work, I try to save the fast stuff for training and races. I am seldom interested in hammering because I wear street clothes and don't want to show up to work all sweaty and tired. I will be moving further away at some point in the coming months, at which point the requirements of comfort (i.e. wearing bike clothing) and the opportunity to get some training in on the commute might cause me to change my habits.

I can practically guarantee you that they can't and aren't maintaining 25mph unless they're referring to a slight downhill section of their commute.