How do I know if I'm in love?

when you accept the other persons idiosyncrasies in the beginning ,but later these same idiosyncracies annoy,pester and irritate you

Ask_Sean Says, Trust me you'l know when your in love.

There's not just one state of mind that is the same for everybody that you can label, "love." Love is about two people mutually meeting each othe's needs, emotionally, physically and sometimes materially. The many variables make the formula different for every couple. One good sign of love is when you are willing to contribute more to the other person than you expect to get in return.

As rossp3313 said, that's not always a permanent thing though. Once the euphoria tapers off, both of you have to work at it to keep it alive.