Where exactly do feelings like this come from? Like I'll often think or say, "It feels like just yesterday I was 14." Obviously, it's been years since I was 14, and I don't even think I really "feel" like it was yesterday, it's just more a figure of speech, I guess? Where does it come from, though?
It's pretty much just nostalgia. Something reminds you of something that happened in the past, or you realize where you are in the present ("Wow I'm ___ years old and doing ____! It feels like yesterday I was ____ and doing _____") and how that compares to where you were before in life.
I'm pretty sure when you say something like that, it's usually when you're nostalgic or something. "It feels like it was yesterday when I first rode a bike..." Somehting like this.
I wouldn't really think of it as nostlgia, when you say "It feels like just yesterday I was 14", you aren't necessarily looking back fondly, just feeling like it was quite close when it was actually ages ago. I think that just comes from vivid memories of that time but of course, you don't remember it as well as you would remember the recent past. Although, it's kind of like the feeling of "It feels like it's 5pm when it's only 12pm"- I think that is a weird feeling but that is just from a day that has started earlier or you've have a very productive morning sort of thing. Anyway, this feeling would be nostalgia if it was coupled with "Man, those were good times, I remember them well!" but if it's just "It feels like only yesterday I was 14" then it's just a weird feeling of a memory. Time flies faster than we realise, I find it really bizarre, I still feel like I should be in year 13... but I am not and I just think that comes from being used to that life style but now I don't have it.
