Originally posted by photoptimist However, I never delete an image for two reasons.
The first is that all of them are part of the (hopefully) upward journey to improved photography -- it's good to be reminded of the failures and any progress toward proficiency. The second is that all of them document the more circuitous journey of life and it's many phases as reflected by the diverse and varying subject matter.
Same here - partly the scientist background, guess: you NEVER delete data (it just might happen to be useful some day)! Well, I do delete absolutely white or black frames, as well as those taken while making other camera measurements (flash duration data and my recent battery use data - the lens cap is usually on!).
As to the original query - I think our brains process old material/ideas in the background all the time. Going back to an old picture completes some of that processing and triggers enhanced memories (hopefully usually fond) of people, places, events, things, ... .