[James]

I don't really understand this concept . . .

Ok, when you first start dating usually the guy is extremely attentive and affectionate because he is seriously into you.

If after a week or two he stopped being that way, you would correctly assume that he is not into you and move on to the new boy.

If after a month or two the same thing happened, you would again correctly assumed he is not much into you and move on to the new boy.

But after 6 months, a year, or two years or whatever, when he is no longer into you and therefore not being all that attentive or affectionate you want to stay and somehow make him focus on you again.

IS there some magical time of investment that makes it just really hard to move on, even though the guy is showing you by his actions that he is no longer into you?

I mean its like once you have an official "title" or he says "I love you" he no longer has to be into you or act like it for you to stay.

Now as a guy, this works for me, but is it rational?

Judge how people feel about you by their consistent unprompted actions towards you.