>>505719305It's something related to the importance of your games in one setting vs the other. Online you'll typically be playing dozens of games back to back without really caring too much and just hitting the "new opponent" button after the game ends, over and over again. At best you'll be skimming the analysis a little but that's pretty much it.
OTB is a whole different story because you'll be playing in a social situation, which is therefore memorable. Maybe even a tournament which just cranks the "importance" meter even higher. You will probably do a post-mortem after with your opponent where you go through things again and talk about what went on. Naturally your brain will keep memories of these events around as something that matters, but it won't really give a shit about your 27th 3+0 game of your nightly degen session.
One thing i can say, and that is related to
>>505718804's post as well, is that playing games you give actual importance to is the way. Spamming meaningless games over and over again does little for your progress. You have to care.