Hello.
Are you me?
I subdivide lists into things like phone calls/mindless filing/housework/stuff to go out and do (collect parcels, take yet more crap to the dump etc)
Also I buy an olde worlde diary and write things in it in advance - so I pick a day for the dump run or when I'm going to look into finding a new ISP and write it in on that day. Also, in terms of movable jobs, the post it note is my friend.
Then I jettison myself into the 21st century and bung a load of alarms on my phone on repeat (tip from friend who remembers nothing otherwise)
Reversing in time a bit (!) I have a whiteboard with long term jobs and reminders on - stuff that needs an eye on it, or isn't urgent but could do with doing before the end of time, random stuff I won't remember otherwise.
I have a calendar (from 2003!) that has everyone's birthday and special days on that sits on my desk, so I know to buy cards/presents/flowers/arrange a party.
When a thing comes up, I have to put it on the 'right' list - so for your examples, the birthday present goes on the internet list (post it note on laptop if urgent, other wise on Word doc on desktop) - the internet list also would include researching yoga. Then the 'next trip to the high street' list would include the passport renewal and also the birthday present. The 'phone these bastards' list would include the call to the bank. I also have a 'call friends' list which is far less combative!
I name my lists in a way that amuses me, the shopping list lives in the kitchen and woe betide anyone who a) moves it and b) doesn't put their own shopping requests on the actual list (instead of thinking I'll magically remember it ffs).
I know this sounds complicated and like I have issues, but it's less so in practice and if I think about it, probably more about trying to maintain a facade of control in my life. Do I have OCD? I doubt it - the house is a mess, I have no idea where my phone is unless I call it, probably I've left the gas on and the bathroom sink has had a bucket under it for weeks because I CBA to have the whole thing pulled out AGAIN to fix it, it can wait till we have the whole bathroom done.
And I've learned to be ruthless about stuff that realistically, just isn't going to get done, so there's not point in putting it on a list.
AND my friend has a GENIUS (imo) system of writing jobs on a folded bit of paper, chucking it in a box with "40,000" (her number!) others, then closing her eyes and picking one out, and doing it there and then. I would try that but I fear I'd spent hours researching yoga and leaving the cupboards empty and mortgage unpaid.......