What I like about the Hattrick community is that there are real people and you don't just compete against the computers. You play against each other, but you can also help each other in the forum and talk about everything.
I would say the community is the strongest reason I have stayed in Hattrick for so long. The game too of course. After having trained my players and played in the French Division 2 for a while, I started focusing on training international players to help the Moroccan team. Today 80% of the defense of the Atlas Lions was trained by me!
A long, long time ago, my cousin showed me this game, because he knew I like strategy games, especially if it is about football. :) And this fantastic game fit my expectations perfectly! That’s how I got started.
One of the best parts of Hattrick, for me, is the fact that you can somehow massively relate to a bunch of fictional players with fictional names and treat them like they're real world players.
My biggest achievement in Hattrick so far is that I have won some titles with my second team in Bahrain and reached the semifinals of the National Cup in Italy, but I hope, a few months from now, that it will be winning the World Cup for the Italian NT.
I am one of the old users who likes to do my own research to learn how the game works. I like that this is a thing in Hattrick. Not everything should be mentioned in the rules. I also like the federations where you can have some real tight friendships. More than some friends call Hattrick a forum, with a soccer-game attached to it.