Calvin and Hobbes by Bill Watterson for July 28, 1986
Transcript:
Susie: Hi, Calvin. What are you doing? Calvin: Big important secret things! Go away! Get lost! Susie: All right dandelion head! Who cares what you do anyway! Calvin: We're doing great things. We're having fun! Hobbes: I thought we were bored out of our skulls. Calvin: Oh hush. You don't know anything.
Looks like in panel one he was having fun with his trucks and cars.