I cannot imagine being creative when interrupted every two minutes! The creativity must have been very specific -- like, "think of all the uses for a brick". Not the kind where you need to sink into your imagination for a good fifteen minutes at a time to allow yourself to really explore what's going on.

On the other hand, perhaps that's the difference between idea generation and idea implementation. You don't need long to think of a good idea, and your first few ideas are probably all crap anyway, so the faster you can get them out of the way without fixating on them, the better. But the creative effort required to implement those ideas... that requires sustained thought without interruption.