As a kid I never used to like change and would freak out when I was told I couldn’t have toast for breakfast, but have cereal instead. There was likely many changes that I didn’t like and now cant remember that had occurred.
These days I tend to expect some change to schedules like through employment as one huge example. I could be working a shift in the afternoon and be thrown out of whack when I get asked to come in ASAP. Especially when all I want to do is sit for a little bit and relax. That is why I tend to get up early as I have that little bit of time to stop from doing things though having that extra coffee might mean I have to rush to get changed for work. The shift changes might get annoying, but at least there is always a roster that you can refer to and then a boss that might be very forgiving and approachable by making changes.
When overseas I tend to swap my usual routines around like I brush my teeth just after getting up as I will go out and have breakfast on the run instead of eating then brushing and going on my way. Those routines might change though I do end up not going out at night as I have other things I want to do.
One of the routines I keep to and try to be ridged about is eating. I will always try to have at least 3 meals during the day and I will try to keep to that even if I do travel overseas to a new time zone. If I keep to that then I will keep my body working, although some locations might not have food and you might have to have a bite to eat later than usual. Work does throw that out too, but still as long as you eat you wont get sick, hopefully.
I do think as we get older we do have to compromise in some way and have to move forward in some way. Sometimes a little change is always for the best. It might be annoying and if you know what you are doing then it might be for the better.