I'd probably drive you crazy, OP. When I feel it, I say it.....but it's often for the same reason you do - because the person I'm saying it to has done something to make me happy, or rekindles the feeling. I've said it so much to my daughter that when I say, "Hey, Boo...." she'll look at me and say, "I know - you love me."
There is that sense of "if you don't water it, it won't grow" as well. I'm interpreting your perspective as follows (so I apologize if I'm wrong): love is permanent; when you've decided you love someone, you'll always love them. From my own flawed, NT perspective, love is impermanent - people fall out of love all the time. So in a way, saying "I love you," is a reassurance we give each other - that we love that person just like we did yesterday, last month, last year. Particularly with a parent/child situation, I'm always saying it to my daughter not just because I feel it, but because that (unlike a romantic love situation) I want her to know that my love for her is permanent (kids need to know that even when you discipline them, you still love them).
With romantic love, though, I think saying, "I love you," also goes back to the idea of telling your partner that you'd choose them all over again, that you're staying with them because you want to, that what attracted you to them way-back-when still attracts you. It's kind of easy to do that by saying three little words.
Last edited by HopeGrows on 27 Nov 2009, 3:51 pm, edited 1 time in total.