The whole concept lies beneath human mentality. If you ever talk to an old person, they laugh all the time for seemingly no reason. What is actually happening is that they have so many memories attached to one small thought they can't help but feel overcome with emotion.
In fact, if I say a sentence like "the big black cat crosses the dark city road" you have an exact idea of what's going on. If I say the word "black cat" the ideas are more and more vague. If I say a word like "innocence" then the ideas which can come to your mind are infinite.
Basically, the more compressed we make words, the grander scale they can transcend.
It is a big regression for literacy, but a huge advancement for communication in general.
As you can see with my "big black cat" sentence, it is more something from a novel or other descriptive work but will eventually be replaced with a single emoticon.
A cool example pf this is the emoticon: 69|O_o
Which means "I heard you having sex in your room last night" which itself can mean so many different things to anyone.