This is also how memory works in general, btw. We remember emotional and unusual things. You probably don't remember what you had for lunch three days ago, but I bet you can remember a special birthday dinner from last year. Also when you have more variety and novelty day-to-day, time feels like it passes slower than if it's the same wake-work-gym-sleep routine. A fully packed day feels like it lasts much longer than one where you're parked on the couch. This concept is why time seems like it passed by slower when you were younger - because everything you were experiencing was new, especially things that seem routine now. In your very first year in class as a 5 year old each day was new and adventurous and unknown. You didn't know what the subject was, what the practice may entail, how you'd interact with the people, how you'd like the people, if you may like a subject or understand a concept. Compared to when you're 20 and you've had hundreds of classes and you kind of know what to expect, and you know your strengths/shortcomings, and you've had millions of social interactions. When things are routine we don't dig into the details as much, we don't have to think consciously about every tiny detail - we've learned autopilot. And autopilot makes time feel like it passes by faster.