There are two things which especially puzzle me; confuse me, even; despite that I think we all experience them.
The first is the way in which time is not linear.
OK, we know that time works only in one direction: it marches inexorably forward. As far as we know there is no way in which time can run in reverse; physicists tell us this doesn't accord with the laws of nature they know about, hence our continuing quest for time machines.
But we all know from experience that time is not linear. There are days when one gets up and follows one's normal routine — some combination of coffee, shower, shave, hair-do, feed the cat etc. — only to fine one is 15 minutes late leaving for work/school. The next day you'll do exactly the same and be ready 15 minutes early. Some days the afternoon disappears without you realising; other days it drags and you seem to be checking the clock every few minutes wondering how many hours have passed.
Scientists tell us this is impossible; that time is perfectly linear. Yet we all experience it. And no-one so far can explain it satisfactorily.
The second puzzle, which may be related to the first, is the nature of days. Again no-one to my knowledge has ever satisfactorily explained this.
How is it that on Thursday, I was convinced it was Friday? Yesterday (Friday) morning I thought it was Saturday. And by yesterday evening I thought it was Thursday again. Worse, yesterday evening (what time I was existing in Thursday) Noreen was convinced it was Saturday. And today? Well I have no clue; my head is just too full of cold germs to be sure of anything beyond it's dark, it's raining and I'd rather be huddling under the duvet.
Now I can understand how it may be possible to explain the way in which time passes faster as one grows older. The theory is that as one ages there is less new to take in; the brain measures time in notable experiences; hence as there are fewer, time seems to pass faster.
But that doesn't explain the non-linearity of time at either the level of minutes and hours or at the level of days. I've been pondering this for years, and still have no idea what's going on here. Is it just that all our brains are faulty, or is there some underlying system of local time-warps? Has anyone got any clues?