Why do people say “Shit happen.” So much. It’s annoying.

My late father used to say that to us all the time and wasn’t afraid to be straightforward and blunt with us. Sometimes too brutally blunt that hurts our feelings.
Even my older half siblings say it (ages 39 and 35). Why do people keep saying that.
Even when I went though my first break up, my dad said, “Well, shit happens. We get our hearts broken. I told you that boy was no good for you.”