A self defense mechanism that tris to keep you in your comfort zone and often restrains you making you feel safer an an environment you already know, while having fear of what you don't know..

I do believe also fear is more often felt when you have a lot to lose, or when you have something so precious for you (not just material things, can be also a bond with someone) that just the thought of losing it it's  something you feel you couldn't handle without a big recoil and probably prolonged pain.

Of course since it's a human emotion, I don't believe it's good or bad itself, and that is a tool we have and should know how to handle in order to avoid useless pain, or to avoid being to much static because of the fear to feel pain.

If you feel you have anything to lose, you don't have any fear, but I do believe a person without any fear, xould be a dangerous person.. cause when you don't have anything to lose, you also don't have anything lo live for, equilibrium is always needed IMHO.. ☯️