I hate slow leaks because they are never really enough reason to change the tube.
Day One after full tire inflation is good. Day Two is good. Day Three is pretty good. And then you use the other bike for Days Four and Five and when you come back to leak-bike, hey, it's not so good.
And you'e already running late, and the floor pump isn't where it usually is and you really do need to ride this darn leaking bike. So there's a great flurry of activity, questions shouted upstairs about the location of the floor pump and replies in the order of "Aren't you going to be late?" and after finding the pump, pumping both tires (yeah, the other one needed some air) and with rim dust on both previously clean hands, you head out to the road.
Yeah, I should buy a new tube. They're what, six bucks? But pumping the floor pump is absolutely free, and the tire is good for three days, and then another three days, and another, and pretty soon, it's time to switch off to the studded tires and you have to take the wheel off anyway, so wait to change the tube until then. (Or if you're really ambitious, find the leak and patch it.)
So we make the tube stretch.
This makes me sound like a lazy cyclist. Hey, if I was truly a lazy cyclist, I'd take the car. I'm just a cheap cyclist.
Which is why I'm riding a bicycle in the first place.