There are people who are not scared to risk being hurt if there is a chance to be truly happy, but “the most of us” cannot tolerate to take this risk. It is like a preventive strong mechanism of defence is activated in order to protect the person from deep feelings, no regards if they are good or bad ones.
Emotions are very hard to build but are easily lost, by just one mistake.
Being practical is sometimes hard in the beginning but it eases life in the end...