If I see someone, I nod or flash my lights or wave to everyone on two wheels. Being on a scooter, I get about an 80% return, but there is a regular guy commuting the other way I see that has never acknowledged me, not once. I don't know whether it is because he doesn;t feel I deserve it, or because he is too young to know about it. But I will continue to do it.
I nodded early at some guy on a massive touring bike the other day - his eyes stayed glued straight ahead, lol. Was very funny.
But soietimes in the dark and rain, I just don't see people early enough. Mainly because they are so close to the car in front of them - stay safe in these conditions guys, leave yourself the braking space, leave the tailgating shite to others