I realize it's easier to leave than to be the one who gets left behind
It is a very lonely feeling to stand there and watch a person leave. To want to say "please stay," but you bite back your words, because you know nothing would make that person stay. If a person wants to leave, let them.
I am not sure which is a worse feeling: to be left behind and regret ever meeting them, or, despite it, feeling glad you actually met. I wish I had said at that time, I am very glad we met. And I don't regret a single moment being your friend. But I wish you had stayed, though, because I probably would have stayed too.
I have detached many times, actually. I have cut connections with people too, because that is what I had to do. I am no stranger to it. So I actually understand it. I don't blame them either, that's why, for leaving. I have done it before too. If removing me from your life improves it, I support it.
But I can't deny my own feelings, though. I can't deny that it still makes me sad. I can't deny it is still a little bit hard.
But as I am writing this post, I must derive a lesson from this. I must remind myself, some people are meant to be a small chapter in your book, never the whole story. There is no shame in feeling sad about it, either. You can still carry the small fragment they have given you and keep it. You can keep the happy memories and allow yourself to slowly let go. You don't have to let go now from your heart if you can't. It's okay, closure takes time, actually.
But I really wish I could tell you how happy I was to have met you.