"It's not you; it's me." Class break-up line right? Maybe even cringe-worthy.
We tend to think of it as an excuse when people don't know what else to say, but maybe that's a bit harsh because it's often true. It doesn't mean there's anything wrong with either of you; you're just not necessarily right for each other.
What about this one? "If I'd just met you sooner…" or "I'd totally marry you in ten years". Yeah, it doesn't feel any better, but think house hunting. Maybe this particularly house would be great in five years, but it doesn't work for you today because of some circumstance--proximity to a school or an infant that needs a room close to a master bedroom. Ultimately people's needs change.
That brings me to Query Lesson #3. Whether we're searching for a house, a job, a friend, love, or an agent, sometimes, two things drive the match: "fit" and "timing."
Or it might have everything to do with you. What I mean is that you might have a well-written novel in a genre people just don't love. Maybe what you're selling just isn't as marketable. I felt that with my second novel. Feedback was good, but I got the sense that it just wasn't an exciting enough theme.
Timing matters, too. You might have a fantastic manuscript, but the market is currently flooded with similar novels, causing agents and editors to pass. Again, sometimes, it really isn't about you or your work. I've said before that my goal isn't self-publishing, and I do think there are plenty of people who go into it for the wrong reasons, but the issue of market timing may be one strong reason to consider self-publishing. If current market demand is high for angels or werewolves or ghosts or whatever, you might assume that agents and editors have a complete list of them already AND they are still receiving umpteen queries a day in that genre. It's just bad timing.
I'll go back to the job market. It's hard not to take it personally when an interview doesn't work out. We all want to be liked and accepted, but because it's about fit and timing, the key is not to take it personally.
Take whatever lessons you can from the experience and move on.