It is not something special to life regressions in particular, but is more linked to your state of mind I believe. The thing about time is that it is not a constand, the illusion is that it looks like it is. Sometimes an hour feels like it takes forever while other times it feel like it passes in just the blink of an eye, so how long is and hour really? that is the real question. If it was a constant it would always feel exactly the same.