The last two times I was intensely emotionally involved with someone, things went badly for me. In both cases it took me around a year and half to recover. What this experience has taught me to be extremly cautious with getting emotionally involved with people.
The way that I'm being cautious these days is to not get involved with someone whose interests and belief system doesn't match with mine.
For instance, I had a friendship with one of my ex's but as my obsession with reducing my car dependence increased, the sense that every activity with her required driving places grated on me. So I became increasingly reluctant to spend time with her.
So at this point I couldn't get involved with someone who didn't at least get my reasons for why going car-free is an admirable goal. They don't necessarily have to be car-free, but moving that direction would be nice.
I then began to despair of meeting someone woman-gendered person who is attracted to other women-gendered people and is willing to put up with both my trans history and my rather unusual ethical/political choices.
However LJ has taught me that such people do actually exist. (Though if I believed LJ, none of them live in the united states). Getting involved with the bicycle advocacy group is even better as some of them actually are car-free. (Even here in Los Angeles).