You know more about Adventure Time than Pen or I do, so you probably celebrate Premiere Day every year with a giant party.
From the postcard back:
You are one of 200 people
to receive this limited edition
Over the past twenty years I’ve been involved with a lot of cartoon series, with some just at the seed stages, on others over the course of entire runs and beyond. In every case, though, I’ve considered myself gratified and thankful to be traveling in the cartoon cosmos.
Created by Pendleton Ward
Cartoon Network Premiere April 5, 2010
Series 21.19 [mailed out June 20, 2014]