I’ve been worried about having early onset dementia since I was 39. My doctor told me I was just trying to remember too much and something has to give. I have real trouble remembering events. My daughter and I share a calendar on our phones. She’s 33 and forgets things as often if not more than I do. I add reminders to my events. I have a doctors appointment at 8.30 so I’ll set up an alarm to remind me at 7am. That gives me time to shower and get dressed and get there if perchance I have forgotten. I think they call that an “aide de memoire”. I look at my calendar every morning. But like you, I get busy and forget I had a class in the afternoon!