when youve experienced something better, you wont want to go back to what you originally have, or started with. having once got As and Bs, you wouldnt be content with Cs. which is why we are all so seh this semester, for fear we get Cs.

and i believe the same feeling applies to love. so maybe there is a basis for 好马不吃回头草。as it logically follows that we all move on to greener pastures.