It's pretty common to all fiction that subconscious thoughts and memories happen in a flash, much faster than, for instance, the time it takes for me to think up this post. These thoughts and memories are always incredibly detailed and often more fully developed than our conscious thoughts.

Certainly this is totally unrealistic, but it's such an accepted trope that probably everything from Star Trek to The Flintstones has used it at one time or another. (Okay, maybe not The Flintstones... )