I carry a pocket knife, have for years, and I use it (whichever one) every day. I open boxes, envelopes, cut flower stems, open pill bottle plastic and trim the foil off wine bottles, open mail, whittle. Oddly, I didn't in the Navy nor in grad school after that, but then I reverted to my childhood habit of carrying a pocket knife and have for decades. I prefer carbon steel, but often carry stainless if the size and blade is otherwise right. I don't know if any of this is superstition or just practicality.