Not "attaching" vs. goals/massive action

I am struggling to reconcile something I’ve heard around these parts, but maybe not from Brooke herself? That’s to not “attach” to an outcome. To me, that means to just want it but to be ok if you don’t get it? I guess I’m not entirely sure what it means.

Then there is setting goals and taking massive action to reach them. Which is in my limited understanding is exactly what it would be to attach to the outcome.

I’m certainly missing something – Help me understand? Thank you!