When to practice Attached Detachment?

I have been hearing many philosophies and/or, philosophers around the world talk about practicing detachment, rather attached detachment. While I agree the essence of it, there's this question always in my mind - when to and why - practice it? Before going into the "when to" and "why" aspects of it, let's talk about a bit about attached detachment. 

Attached detachment is while being attached to something, detaching yourself from the result of it. For example, if you like a certain someone, attachment part comes in liking them, whereas detachment part comes in actually not getting attached yourself to the result (as in, not expecting them to like you back, instead leaving the results to the greater Universe!). If one can practice this concept at all times, then the chances of getting hurt are practically from 0 to -10. 

Have you ever wondered what life is without any hurt or pain, at least intermittently? Yes, we will be happy and peaceful all the time, but isn't that the worth of peace and happiness is known crystal clear when we actually experience the opposite?

So, the question is when to apply "attached detachment"? My answer to that would be, when you know you are being pulled towards great pain and chaos which can cause negative effects in your life - move away from the object of attachment (object can be anything - a person, a career goal, a monetary goal...) and practice detachment while still having your attachment in tact. .