I have noticed that being around IXFJs seems to very much increase the Fe level of ENTP men.
I dont know why but it appears externally to almost amplify the Fe way they interact with others. When the pair interacts, you can almost see the interaction and how each becomes more and more engaged as they exchange happy Fe vibes.
So maybe you always knew logically what you should do, and had a rudimentary sense of Fe, but you and your girlfriend sort of help grow/develop and strengthen each other's Fe and become more caring to everyone around you in the process???
I dunno, I am Fe blind, just a guess. I can see how this would be the same for two Fi users as well.