When you missed an episode and someone you know has seen it, you sit them down and force them to tell you EVERYTHING about it, while grilling them with questions.

You've seen every episode and know the names of all the Digimon and their evolutions

You tape every episode with Matt in it

You end all the names of your friends with "mon"

When anyone mentions the name of a Digidestined, you grin inside and chuckle.

On the highway, you see a company named Yamato and get your mom to drive by it over and over again in hopes of seeing Matt

You dream about it.

You get into heated discussions with Pokemon fans.

You use your Boggle pieces to make a puzzle with the names of all eight Digidestined, and then rearrange, and then rearrange...