What was a hard decision the Little Prince had to make?

The Little Prince makes the difficult decision to travel from his asteroid planet, because it means leaving behind his beloved rose. He departs the tiny planet because he feels he needs to broaden his horizons, but also because he can't bear to be with the rose anymore, even though he loves her. He wants to escape how demanding she is. It is also difficult for him to understand her. He feels he always has to protect her and put her under her dome, and yet she often makes cutting remarks to him: he doesn't understand that this is her way to show she loves him. He has to go away to gain perspective and understand why the rose matters. Because of this difficult decision to leave he learns how important his asteroid is, when before he thought it was trivial.

Another hard decision the Little Prince makes is to let the snake bite him so he can go back to the asteroid. His body is too heavy to make the trip back, so he has to get rid of it. The Little Prince himself calls this act "difficult" and says it will look as if he is dead, but notes that the "important thing is what can't be seen."