What would happen if i visited a place a few months before and then later realised there was an earthcache and could answer all the questions correctly. I still learn about the geology but i didn't think about it at the place. Does it count as a find?
FWIW, the second to last item in our FAQ addresses this topic somewhat:
Somebody logged my EarthCache, but it appears they visited the location before my EarthCache was published. Should I allow the log, or delete it?
There is no rule that says somebody has to visit the location after publication in order to make a log.
HOWEVER, in GSA’s view, somebody has not actually visited an EarthCache if there was no EarthCache there at the time of their visit!
GSA has no problem with a cache owner deleting a log from somebody who has clearly not visited the EarthCache after its publication date.
If a cache owner wants to allow such logs to stand, that's fine too. (That's up to the cache owner. Maybe in some cases they would feel as though the person logging the cache did get a good lesson, by combining an earlier visit with solving the cache's logging tasks after the fact. The cache owner can be the judge of that.)