I think I can as well remember seeing the post you're talking about, it was a welcome/introductory post right?, I believe so, cause in my mind's eye I can remember you starting with 'I am Satyr' or something along that line.
Well, it's basically simple what happened if that post is missing, it has actually been deleted by a moderator, but hey do not get all upset about it, it didn't break the forum rules, or else you'd have been banned by now, it was just low quality stuff, that's not to say welcome posts are generally LQ or are unacceptable, cause you could see other post of that sort and start a similar case to that, it's just that yours wasn't really important or that you didn't say too much for it to be acceptable, see this excerpt on introductory threads:
If you feel the need to post an introduction thread please take the effort to write something substantial or don't bother at all. Threads and post that contain only one word/sentence such as "hello & welcome to the forum" will be removed without warning as it causes unnecessary clutter.
But hey, the good thing is you can work on improving, that's not to say you'll have to make another thread introducing yourself, just adapt more to the forum and develop your knowledge of Bitcoin and other crypto, so you can start making High/medium quality posts, you can also read this:
Bitcointalk Posting Etiquette.