Um.... okay:
Truthfully, the first anime I ever watched was Pokemon. But I didn't become or start calling myself a weeb or anime fan until I saw a girl from our class draw a very detailed picture of a female Katsuki Bakugou and I asked her "Hey, that looks good! What is it?" and she said "Oh, this is just a character from My Hero Academia, in canon, he's a boy. Hey, you should watch it! I know this character that I think you'd really relate to!" And that one sentence changed my life forever. I didn't watch it immediately, and before I did, there were a lot of MHA references around me it's like the whole world was screaming at me "Watch MHA!" There was a guy who wore this MHA jacket and a MHA bag. The first glimpse of My Hero Academia I ever got was the time Deku met Uraraka and I thought "Yup, these two are the canon ship. They're gonna end up together." I watched the series and it was AMAZING! I totally related to Deku and how he got bullied in Junior High.
AND THAT is how I became a weeb.