I don't think I have problems sleeping in general. On a normal work day I'll fall asleep sometime between 10 and 11 and wake up feeling fresh. I don't set an alarm.
But it's becoming a clear pattern that the night before big climbs, especially when I have to wake up early the next day, I barely sleep at all. Either I will struggle to fall asleep or I'll fall asleep early but then wake up around midnight and not sleep any more. I won't feel sleepy at all, and I'll just keep rolling over. Reading sometimes helps, as does listening to dry podcasts, but I've definitely had nights where I've listened to three Guardian longreads and an Enormocast and could describe them all in detail. Huts exacerbate the problem but it happens even if I'm home in my own bed.
The flip side is that I've learnt I can function perfectly well with almost no sleep. I don't generally drink caffeine at all, but after a strong coffee after a sleepless night I feel fine. I climbed Mont Blanc yesterday on three hours' sleep. But this seems unhealthy in the long run.
Anyone else have similar issues? And any suggestions about what can help?