I thought I understood what a
Verb and a
Verb + lassen mean (somehow influenced by this question), but I don't. My previous idea was that one writes
Verb + lassen when the action is not performed by the subject, but by third agents:
Karl lässt sich die Haare schneiden.
But I heard the expression
Ich würde mich trennen lassen.
in the context of getting divorced. The subject decides that he/she wants the divorce. Why does one use lassen?