What moment specifically?
For me, I think it was when my friends in school showed me how to actually play and navigate through Neopia. I spun the Fruit Machine for the first time and I won a paint brush which shocked my buddies. After that, I found myself going on every day to do the dailies. Then my one friend showed me avatars and how to get them. I wanted to get them all! I was hooked afterwards for many years.