monpot invented this tradition back in 2005 I think - with his 3,000th post if I remember correctly
the correct procedure is as follows...
with your 3,999th or 24,999th or 39,999th post you post your thread in a
'my next post will be my 4,000/25,000/40,000 - ask me questions'
then you leave a decent amount of time for the questions to pile up or give a time limit in your original post and then with you x,000th post you answer ALL the questions
This is the monpot law
please respect it