I know a wise person taught me here, when something no longer serves me, when it is causing me more pain than anything else, it's time to move on. I don't contend that I will ever get full closure or the closure that I'm looking for, but still, when it aches more than it helps, it's time to close that chapter for good.
If this is pertaining to a relationship....I would say when everything you have done, tried and you have completely ran out of resources for any more solutions is when you step back, see things as they are, accept things as they are knowing you have done every possible thing to no avail then you plan on what to do for yourself.
I made closure for myself...my husband made no effort so i gave him a time limit to show effert and when he showed me nothing i said right thats it we call it a day..I'm now divorcing as time is too precious to waste...
First question: you just know. <br />
Second question: persistence & a little hard heartedness.
I know you should have ended this sooner. but its all learning. I have been through the same thing and it was worse than having a ball and chain to the ankle. people come into our lives for a reason and once that purpose is served, a new one appears. get out there and find the man who deserves "YOU" go for it!