Originally Posted by Raziel

We are all ... Groot.

Via Reddit:

Groot is a giving and helpful character and probably the nicest guy on the team; he doesn't show desire, greed, or "the world owes me ".

Each character has an agenda within the team: Rocket and Quill want money, Gamora and Drax want revenge, but Groot doesn't express any desire but he is prepared to sacrifice himself for the greater good.

He isn't seeking anything, he's already complete and satisfied - a sentiment he makes very clear: "I am Groot."

.