WHAT
It is exactly like that. If you exclude the first few chapters and some rare holiday specials, from Chapter 51 onwards everything you are reading is a very long flashback to the past. We already know, we discover it at the very beginning of the manhua, that the four boys will separate within a few days and will never see each other again, for several years.
HUH I NEED TO RE-READ THIS BECAUSE I DON'T REMEMBER THIS SHIT I'VE BECOME BRAIN DEAD
sht same, i've been all laughs about the recent chapters lately that i forgot sike
I always forget that everything going on in 19 Days right now is just a flashback