Can someone convince me that this problem isn't in your head? I used to consider myself a "night owl" until I observed something: I was travelling in Chile an

Can someone convince me that this problem isn't in your head? I used to consider myself a "night owl" until I observed something: I was travelling in Chile and went up to Peru. There was a two hour time difference despite being at more or less the same longitude (I think Chile shifted its clocks in summer while Peru didn't, and there was a one hour difference on top of that). Guess what? I got used to it in a few days. Likewise Spain is an hour ahead of the UK, despite being both being similar longitude. We shift our sleeping patterns by and hour a couple of times each year with daylight saving. It usually only takes a couple of days to get used to it. I enjoy my sleep and the answer seems to be going to bed earlier, and not convincing yourself that you can't sleep because its too early. The time of day is a social construct.