Trust

Trust is something you have to earn, however once you lose it, it's gone, not forever, you still can try to re-earn it but it'll be infinite times harder than you got it at first. Always learn the easy way, don't make yourself and the people arround you suffer, learning through the hard way makes you lose friends and some mutual trust between you and the other parties. In this modern society, mutual trust is something that is equally important to the water you need to drink in your daily life, because without it, you can't survive. So, always think before you want to break off all relationships with another party, because at the end of the day, you might end up the person regretting.