Why do happy moments make me sad?

for me it’s because the feeling of being happy is so foreign that when i do feel it or i see something that should have a happy response it makes me sad instead bc i miss the feeling or i feel upset that i can’t formulate it

Me too. For me, I think it's because I have no one to share it with. Joy doesn't last very long when you can't share it.

For me it's the feeling that you know they won't last and not getting too excited to try to minimize the hurt when I drop again

For me, it makes me really sad that I still don’t truly feel happy, which starts a negative loop of “I’ll never be happy. I don’t even remember what happiness feels like”. Or, if I get a glimpse, it’s sadness mourning what feels like a fleeting moment and grieving what could be but isn’t, feeling things will go back to the way they usually are and it’s so hard to get those moments back. It also feels like life is passing me and I’m missing it and then going to die and not have taken advantage of life.

For me, when I experience my happy times I get the same feeling but I think because I know at some point it’s going to end, because it usually never stays. It’s like now that your experiencing an high and you know it’s not forever. I relate to this a lot. I wish we didn’t feel this way though.

I feel this. I think after so long of feeling depressed or numb happy can feel uncomfortable about make me sad. I think it just takes time to get used to again. At least that's my experience with it

It’s possible that you are sad because they are over and you miss the sense of joy from them. Maybe something has changed that makes that same feeling of happiness harder to obtain, essentially mourning what you’ve lost since then.