Sorry Jim.
My dad, who had a similar mug, was a mostly gentle soul. As a very young kid though, like many others, I was scared shitless of him. He had a presence and a voice that made me tremble. You'll understand this part, he owned a restaurant with his sister so he was rarely home. Mom used to call him when one of us three boys did something stupid, which was often. He'd have to pull himself away from whoever he was serving (he ran the bar) and listen to my mom who would then give us the phone. The offending child would get read the riot act. Sometimes the conversation would end with my mother uttering "wait until your father gets home!" One of those times dad came home for his afternoon nap before heading back for dinner. I was the one in trouble and I apparently pissed my pants when he walked into the house. I was too young to remember this, but, now some 50+ years later it is a story that gets told to my kids every time they see one of their uncles.
Then there's the time I borrowed a bulldozer...