Mudguards and riding a single-speed do it for me.
I don’t mind the being wet bit, but I really don’t like that raccoon-stripe of filthy road slop up my arse. Mud / grass et cetera is fine, but that horrid stinky mixture of grit, diesel, oil, and who-knows what else flicked up from the tarmac is just vile.
Hmm … that said, I *do* mind the being wet bit if I’m miles from home on a mid-winter’s late-afternoon when it’s getting dark, even colder and the wind is picking up, and when I’m already chilled, soaked, stiff and hungry / bonking, and starting to get a bit muddled. I’ve found that’s been pretty miserable … but as long as you don’t get too muddled*, I find there is motivation to be had in the simple fact that stopping now without food / drink / shelter / being dry, can only end badly vs, digging deeper and pushing on to somewhere that’s dry and out of the wind, with food and drink and the chance to recover for a bit (or just getting home).
The self-motivational challenge really kicks in there tho’ if the looked-forward to shop/garage has closed down for the night (happily less common these days), and/or when you get a mechanical.
*Once it’s happened a couple of times, you get to know the signs, which helps. 😯