Sadhguru
Why does a break-up hurt so much, even when I can't stand the person anymore?
Why a break-up feels like tearing yourself apart
When two people have shared emotions, body, sensations and living space, their memories merge, so ripping it apart is almost like tearing yourself apart. It hurts even when you can't stand the person anymore, because you are a bundle of memory. Conducting the parting gracefully and well is important, and so is doing inner work.
Still it hurts, simply because you are trying to rip out a memory which is you, because you are a bundle of memory.