I guess it happened with my second boyfriend. At the time, though, I thought I meant it; however upon reflection, I think I was trying to rationalize the feeling the entire time, and think I knew on some level that I was trying to will myself to love him, and it wasn't something I truly felt. It became apparent in the dynamic between us that I didn't really love him, and it ended within 6 months. So I've been very careful ever since not to get into the rationalizing-my-feelings thing, as I'm susceptible to that.
"...On and on and on and on he strode, far out over the sands, singing wildly to the sea, crying to greet the advent of the life that had cried to him." - James Joyce
I have a problem with people at my church throwing it around to others. In my mind I am always like "What purpose do you love me?" I know one guy who is very emotional (more than likely ESFP), effeminate-like, who throws around "I love you" to everyone. I don't like it at all. Perhaps it is more to be a religious service to be Christ-like. You can love everybody, but you don't have to like everybody is my guess, and the concept is when you say "I love you," you will eventually mean I guess what others think.
I made a comment similar to the OP's on Facebook about 3 months ago and said I prefer acts of love instead of your words because actions speak louder than words. Not the exact words, but something along that line.