I must confess I skipped some of them (I promise, NOT many!!) which I watched earlier. (I'm not such a fan of Thor: Ragnarok, even though I'm a HUGE fun of Cate Blanchett; Winter Soldier din't steal my heart, in opposition to Guardians of The Galaxy, which steals it again and again and again!) I just gathered some important detail from dozens of YouTube videos explaining us, what we "definitely must have missed!".
I enjoyed the ones I rewatched much much more than the first time. There was some kind of continuity (BEWARE! NOTHING to do with how the movies were released!), it's nice to understand why this or that happens. Also during such a marathon one gets involved more, feels more connected to the characters. Well, I did, and how about you, @philh ?
And so, yesterday afternoon, when Endgame was over, I thought "That's it! No more...", just to find out, while opening the list again, that there already is movie number 22!?!?!?!