February 25, 1952: "Yes sir, this shampoo is just the thing for your fleas."

In the Peanuts backstory Charlie Brown's father is a barber, which mirrored the occupation of Charles Schulz's real-life father. You can't be blamed for not knowing this fact as it seldom factored into the strip in later years, perhaps due to the awkwardness of making use of the fact after Schulz's own father passed on.