When did people first say "have my wits about me"?

Search: "wits about you" origin

Why: A friend refuses to lol at my jokes because he's trying to teach me a lesson.

Answer: The 1600s! except I don't think these uncited examples are from then:

• After the collision I had my wits about me and got his name and license number.
• Being followed was terrifying, but Kate kept her wits about her and got home safely.

unless the first is about a carriage collision and the second is about a damsel who really shouldn't have been walking around by herself in the first place.

Source: Dictionary.com

The More You Know: Do you know what it means?

To remain alert and observant; be prepared for or equal to anything: to keep your wits about you in a crisis