I used to go to TRU league too, but I didn't start until the Johto season (although I first got into Pokémon shortly after R/B came out). I still go to league, but not there; they stopped hosting it around 10 years ago, and that TRU isn't even around anymore.
Lol @ the poison "glitch"... I thought my batteries were dying when I first saw that. :p
I've been to Worlds twice, but not as a competitor. It's awesome! The hotel is full of Pokémon people and there's people playing in the lobby and designated gaming rooms at all hours of the day, they have special guests like Mr. Ishihara and TCG card illustrators (who will sign cards for you if you wait in a long line), and you get to meet lots of interesting people from all over the world. They have a shop with exclusive merchandise, and the Japanese TCG players trade/sell some of their exclusive stuff too. If you volunteer to work at the event, you will get compensated very well!