Watch a girl age into an old woman before your eyes thanks to this neat simulation. I don’t have details on how they did it, but it does get you thinking about how poor we are at perceiving gradual change.
Try this trick after you’ve watched the whole video: click back 30 seconds, and then 30 seconds before that, and so on. Your brain will have no trouble seeing the transformation when it is done in significant jumps.
This explains why hindsight is often so much clearer than the present.