Kirk and the Keeler Elf knew each other for how long? A few days at most? Real love takes longer than that, in my experience.
Plus from what I remember this whole Nexus thing and how time works there is so nebulous, do we know whether the whole country house/horse riding thing it was the only fantasy scenario he lived through?
I think the amount of time Kirk and Spock were there was at least a few weeks. It took Spock days to build his gadgets to work with the tricorder the first time, and they would need to have built up enough funds to buy all the stuff he needed to make it work. That takes time.