What is there to do in minecraft?

I've made like 5 different worlds. I get bored after i build a house and make a wheat farm. Seriously, the starting bit is like the most exciting part and then it's boring from then on. Once i build a house there's like nothing else i wanna do. Not really keen on making anything else. Can you grow other things besides trees and wheat?

If you get bored with the normal stuff, try mods. If you can't do that, there's tons of fun maps people have created for others to play. One of my favorite to watch is Islands of Junara.

Two words.
Multiplayer servers.
Multiplayer never gets boring!