
My mother taught me, so long ago that I can't even recollect the .wav of her voice saying so, that "love" and "hate" were the two most powerful words to say, about another person. Perhaps at the same time, perhaps in a different lesson, she said that you should never say you hated somebody, and you should be really careful that you really, really meant it if you said you loved someone.
If I say I love someone, it may be as a friend, a sibling, a lover, a parent. It's an unbreakable bond. Once you've loved somebody, you can't un-love them. You can change the way you feel about them, you can even learn to hate them, but the echo of the past love will always be there, unerasable until the personality dies. Even then, there will be some few hardcoded things remaining of the love.
When I say I love you, I expect our friendship to be the sort that we may not speak in years, if we lose contact, but upon seeing each other once more, we will resume the conversation almost where we left off, with of course catching up to do, but still, the same level of information flow.
When I say I love you, I expect I won't fall out of love easily. When I say I love you, that won't change unless you change it for me. Of my relationships in the past ten years, I think only BJ has made me unlove him. Even That Idiot Shawn, on some level, I still love.