Using a Planner and Remembering Appointments

The Internet will tell you that planning is awesome, because you can use your planner like a brain. You don't have to remember things, the planner remembers them for you! There needs to be no worries of that appointment next week, or errand you need to run - your planner knows about it, you don't have to any more!

That is...allegedly true.
I can make no claims to that.

Because, for me, it's not true at all.
And it is quite saddening. Because planning was supposed to help! And it, well, hasn't in that regard.

For example, last week I had to go see the Mister's Uncle for something or other, and it was for Monday between 10 and 11, depending on when I left and traffic and whatnot. So, I wrote it in my planner. Awesome, ya? Ya.
Except for the fact that I remembered it for the next few days, then managed to forget, and then remember while we were out and about the day before (Sunday) before I had done my planning for the week (as in without the use of my planner to remind me).

Sometimes, that can be awesome. Not going to miss any appointments, which is always nice. But not nice in the fact that I don't get the mental space and energy back.
I was led to believe that I would!

I want to not have to worry about things or places.
I would enjoy not having these things randomly pop into my head - because it means they were circling around, waiting for the correct time to jump out. Which means that's energy I could be using for something else. I dunno what else - probably because I'm still holding that information!

Or, maybe, I was just misled. That's probably it.
There's no way that other people are entirely forgetting their appointments. There must be an inkling before them of "oh ya, that's tomorrow" or some such without a planner reminding them. The planner is just to have an extra backup, or a way to remember after the "oh ya" fades away (as most of my "oh ya, I need to"s do - before returning at least a day later, of course).

Let me know - do appointments and things stay in your head until they happen, or do they absolutely need to go into your planner?

~Havok

P.S. Don't get me wrong, I forget about a lot of things. A lot of things. But, places I need to go do not fall into the category of forgetting before it is time to do so. Now, forgetting to, say, do the laundry - that's a case of selective memory ;)

P.P.S. I also believe me not being able to "forget" this kind of thing has to do with my (almost) phobia of being late (or even barely on time) for anything. If I don't forget about it, I can leave on time, which means I won't be late. Or something like that.