Too much love kills the love

A couple of days ago, during an exchange of messages, the above 'quote' was mentioned as an example.. It was a first time for me to hear and it made me wondering if too much of something could kill this thing? How and Why?
If we check our daily life, like for material and physical things, it is more or less correct. Too much smoke kills or at least would affect the health. Too much water could kill the plants...
But for the non-material things, is it the same thing and why?

I think it is related to the fact that the human being needs constant change, whatever in the rythm, in the activities and to be unique.
Too much work will make us hate working and kills the ambition to excel in this domain.
if a person talks a lot, we would find that he/she becomes a boring one, with all the stories repeated.

but back to the quote that intrigues me, Too much love kills the love. Why isn't the same with hate. Wouldn't be great if the too much hatred in this world would vanish just like that? does the person have what is called a "normal selection" to which feelings are good to fill life with them and which may lead to the "self destruction"?
or is it related to that the excess of something could ruin it all? as per the prior two things, a perspon needs change and uniqueness.