This happens, at least, on a weekly basis even when no mistake was made by da worker. It's all very simple: I'd endure for as long as I possibly can yle priv8ly mocking da bejesus out of my boss!

Silly That's quite mild. My boss once told me i didn't come to work with my brains

You all must be pretty dumb or remarkably stupid if your boss finds the time to address your foolishness daily.

There are so many way to deal with your boss in the office if he offended you. one of it is you will change your character against him.

I will do nothing due to i must have done something silly indeed.

Silly can be a nice word man. Check a dictionary. It could mean playful - even though your boss might mean foolish, assume the playful part. It'll make your life easier.

Your case reminds me of when i was still at the university one hot girl who I've not spoken to or seen in my life stopped me and told me I was cute (I felt insulted) to me cute was a word meant for toys and kids, I told her with a stright face - thanks and walked away. The next day I saw her again (this time with her friends), avoided eye contact and moved away.
Later that night, I checked the dictionary for all the meanings of cute and it wasn't that bad.

So pick a meaning that makes you at ease and it the silly word won't affect your performance at work.

start looking for a new job on the side.
or try hobnobbing with your boss and sucking up to him/her.