I would say not just that.. The unexpected is what seems to kill most.. So try to anticipate any/every item that could go wrong (weather, equipment, people, etc) and practice solutions (MOB, dismasting, turtle, bad tide/current, injury, etc)

I recall not being allowed to singlehand my family sunfish until I could successfully right it, raise & lower sail on water, retrieve a lost centerboard, and sail without a rudder. I think I was around that age (12-14 years).