Impossible to move a task list to a milestone?

Impossible to move a task list to a milestone?

It seems to me that a milestone should be part of a task list and not the other way around?

Looks like if a task list isn't created under a milestone, it's impossible to move it to a milestone?

My understanding of a milestone is a date in time when something should be done and not a bucket with multiple tasks and task lists?

Am am thinking of this wrong?

Thanks,