To be creative, we must marvel.
We must not allow ourselves to get used to the marvels of life, both small and great. When we wonder and marvel, we take in every aspect of the subject of our wonderment. Those things we take in, that's the very stuff ideas are made of. When we marvel we take in inspiration; we take in the puzzle pieces that will form the ideas we are still to come up with.
It's a pity that us humans can get used to just about anything. It makes life less interesting. There's a bit of Louis CK's stand-up comedy that illustrates well what I mean – it's definitely worth a couple of minutes:
In a brilliantly funny way he points out how we as a society just got used to amazing things. They don't even really amaze us anymore. It's part of human nature to take things for granted after we've had them for a while, but how can the things you don't notice inspire you, even if they're staring you in the face?