The Heart of the Matter

I was writing something and I was about to use the expression, “the heart of the matter.” Sheepishly, I wondered if I should change the word “heart” to “liver.” Can you imagine if we changed all the expressions using the word heart? We’d have: straight to the liver,stole my liver, wears his liver on his sleeve, liver strings, liver of gold, half-livered, cold-livered, half liveredly, kind livered, whole liveredly, liverless, liver and soul, from the bottom of my liver, liver to liver talk,  broken liver, liver of stone, the liver’s desire, take it to liver, and liver-felt.