Some times the brain is wired to intuit the concept. That's something that fascinates me. You grasp the idea before any articulate explanation. Somebody shows you a problem and rapidly you start discussing solutions with the other person and even go further.

Most of the time memorization is a key role for creativity, the easier you can jump between ideas the more combinations you can explore (seems like the brain is constrained by some cache bottleneck in a way).