I've been watching a lot of Grey's Anatomy lately, just starting with disc 1 of season 1 and playing through the series while I do paperwork for work every night (before I got too sick and was told to stop). I haven't gotten up to the part where this song starts being used, but watching Grey's still makes me think of it. I had actually misheard part of the lyrics as, "Those three words/are said too much/and not enough." Even though I now know the third line of that is, "They're not enough," I still like to think of it the other way, because it's so true. Those three words are said too much by people who don't mean them. But they're also not said often enough by the people that do mean them, whether to the people we love as family, as friends, or romantically. We never know when the chances to say them will end.
This is my favorite version of the song. It wasn't until around when this episode was done that I actually knew Sara Ramirez had been on Broadway before her role on Grey's, but her voice certainly shows the training!