Well, exactly. We know there is some difference, and we only have a vague idea of where we or anyone else that we see on the road lies on that curve. But I would think that any guy who's ridden enough to complete at least 10 mass start races with other competitive and reasonably fit men - and keep at it - would naturally see himself well to the right on that graph of female riders, so unless she's clearly stronger or making more of an effort than he cares to, he's probably going to think he's slacking and maybe needs to pick up the pace. Speaking for myself, if my awareness of my performance is ever alarmed in this way, I just try not to engage in any knee-jerk reaction. But I'm usually not alarmed, I'm usually already aware of how lazy I'm being.