I understand completely, and you're right to question it. The answer is that a lot of these behaviours are pretty normal, and it is very possible to identify with some of the memes even if you don't have ADHD. It's when they just keep resonating with you on a really fundamental level, across your entire lifetime, that you should maybe be suspicious. ADHD has a genetic component too, so it might help think about your parents' behaviours and if they also match.

My psych had me complete this self assessment quiz (ASRS v1.1) before my first appointment for evaluation. It might help you too: https://psychology-tools.com/test/adult-adhd-self-report-scale