I started a new post in FQ, and the new “Your topic is similar to…” window popped with an older post that was exactly what I was about to ask. And I had posted it.
I came here to post something similar, but I forgot what I was going to say. Apparently it’s contagious and you’re a (the?) carrier.
Well, at least you recognized your own username.
The technical, SDMB approved term is “threadnesia”. (We won’t get into the other suggestions that didn’t make the cut. 
)
Often when a zombie thread is resurrected I don’t realize it’s a zombie right away, and I decide to post in it. But I usually do at least a cursory skim of the whole thread to see if I’m the first to say whatever I’m about to say, and find out I already made the same point back when the thread was fresh. I almost did that in a Colombo thread just yesterday— someone had said “Mrs. Columba didn’t really exist, right?” I was about to make a Kate Mulgrew joke when I discovered I already had made almost the same joke awhile back.
Or… I often read on my iPad, with the screen widened for easier reading, so avatars are unseen off the left side of the screen. And I often read a post first, then look at the username. So I’ll be reading through a zombie thread, not realizing it’s a zombie, and I read a post and think “hey, that exact thing happened to me too!” Yes, because it was posted by solost.
Memory is actually the second thing to go.
I forget what’s first.
“My brain? That’s my second favorite organ!”
-Woody Allen
I hope you keep all those checklists and that ol’ QRH handy when at work! 
Personally, I enjoy the fact that I very rarely actually have to remember anything any more. Mostly, I have to remember my grocery list when going grocery shopping (and to put my pants on). Though if I ever forget the grocery list and have to go from memory, I am doomed. You can imagine the utter disaster that ensues – the absence of critical grocery items matched only by the overflowing abundance of unnecessary replicates!
Grocery shopping gets even funnier if you forget your pants. When you go to check out, there’ll be no wallet to pay with. Oops. Imagine how red your face will be then!
“These stockings,” he Grinched, “are the first things to go.”
MERRY XMAS!
I think it is curious that you used the same emojis both times back then but a new one today. That must 
PS: Leonardo and Micheangelo are known by their first names too. Wich I probably would have written and forgotten by now had I answered your threads when you wrote them. I believe I did not, but somebody else probably has, and has forgotten about it. It’s all right, you have forgotten too.
Did I start a thread on that?
I don’t remember why I entered into this thread. But I’m sure it was important.
Out of all the things I have lost, I miss my mind the most.
-S. Clemens
Why the hell did I visit this thread again?
It’s very simple:
Earlier post in this thread:
Northern_Piper:
The technical, SDMB approved term is “threadnesia”. (We won’t get into the other suggestions that didn’t make the cut.
From the thread:
There were several other suggestions, one of which you made:
Qadgop_the_Mercotan:
I dunno, I like Northernesia.
LSLGuy’s suggestion:
I suggest “Pipernesia” for asking the same question years later.
Wow! I totally forgot I said that. But it sure sounds erudite now