Some of them I think imgflip deletes if they don't have many views or upvotes after a period of time. I think I've tried a couple again and had them go through, can't really remember exactly there have been a lot of memes lol. I need to go back and look, I know some of them were bad, it's funny I look back at my earlier photo shop work and cringe. Had to learn somehow I'm just lucky imgflip has always supported me even when I was just figuring stuff out :)