I don't delete photos I took
Do you like collecting photos?
I think that I should keep them for sometime, later.
There is nothing wrong with deleting photos you don't want to keep anymore. However, you should make sure you won't want them at some point in the future.
There is no such thing as trash
There are large storage devices you can use if you want to keep them for another time. That way you can free up space on your camera device and take even more pictures.