In short, I think I've seen somewhere in the literature where Grothendieck similarly said,
What I feel when I do math is that idea is important."
Or, I think I saw that
More important than proof is an idea and, even furthermore dream.
But I forgot where I saw it. Now I can't find the exact source involved. Récoltes et Semailles? La clef des songes? Can anyone guess or tell me the exact data in this regard? :)