When I was in school, I would get in trouble for forgetting to turn in homework. Why didn't I turn it in? Because I would forget I had homework and that it was in my bag. Sometimes I would get in trouble for not doing homework. Why didn't I do it? Because I forgot it was due that day, or I forgot I had it at all. So I was given a book to write down all of my assignments, and when they were due, and check them off when I was done with them, and to review every day so I knew what I should turn in.
I continued to forget to turn in assignments. Why did I forget them? Because I forgot to check my book to see if I had any assignments to turn in, in addition to forgetting I had it and it was in my bag. I continued to get in trouble for forgetting to do assignments. Why did I forget them? Because I would forget to write them in my book, or I would forget to write down when they were due, or I'd forget to even check the book in the first place, or I would forget the book at home, or in the last class. Or I would forget my pen and not have anything to write in the book with and then forget what I was looking for a pen for by the time I got a new one.
Don't get me wrong. I still use books, post it notes and organizational tools to help me in my profession. Bug trackers are a god send for me. But so is the fact that Slack archives every discussion I have, and gmail never forgets anything no matter how much you wish it would. And that's important because I still often forget to write something in a todo list, or the bug tracker. I've trained myself to check 5-10 different sources of "tasks" before I consider something done because I don't remember where I put everything, and I never remember to put everything in one place. Even with all of that, there are still things I'll forget from time to time.
Do you remember old clip art CDs and galleries? They all used to have a clip art of a finger with a string tied around it. That's clip art for a "reminder". I never understood how that was supposed to work, because if I ever tied a string around my finger to remind me about something, I'd be lucky if I remembered the string was there at all, let alone what it was supposed to remind me about. Tools are often just one more thing to try and remember.