I carried my first mobile phone on a business trip in about 1990. “Mobile” was a generous way to describe it. Heavy and large with a charging stand. I had a firm conviction no reasonable business person would ever carry a phone with him on a trip. Too much trouble.
I read in an article about leadership we like to follow “leaders who have conviction.” The article talked about clarity, purpose, focus, and similar reasons to like conviction. What is not to like about clarity, purpose, and focus? But “conviction,” that needs some thought.