The first thing I ever posted was my epic poem,
Ode to an Odd Quest, and perhaps one of the better entries into the forum. I had no welcome thread, this being the first forum I ever joined, I was under the deluded impression that
other people started threads to welcome you. I soon realised what I'd done, but I felt it were too late to do anything about it.
Then I started
this thread in the GD, later moved to the fan corner, where people posted their made-up creatures.
But the most embarrassing early poss I made are probably
here, Abe01's thread about vegetarianism. I feature some rather choice posts on page 2 and 3.
There are some other threads from last spring such as
How close is Oddworld to it's sun? and
They should have Meeches in the game. Long posts were a staple of mine, in which I explained various phenomena in scientific detail, provoking replies of awe, confusion, in the case of used:), a hostile PM.