I mean really thirsty? I'm usually not thirsty at all and only drink because I know I need to.
I have two glasses of water before every run but I can't imagine this keeps me hydrated enough for 2 or 3 hours after the run (which is the time when I get thirsty again).
I know thirst is a sign that the body is already lacking water and I read somewhere that it's best to avoid thirst and drink regularly even without thirst (so that the body never suffers from dehydration) but I definitely don't do that. I always have to remind myself to drink (also on non-running days).
Does anyone know this phenomenon of not being thirsty after a run? And how much do you drink? As I'm not thirsty it's difficult to say if I drink enough afterwards. I'm not having any problems so I just ask out of curiosity.