Actually, it's a classic in which Mike does something silly.
(Strip Number 7089, Original Publication Date, 12 July 1981)
Panel 1: We see Mike trying to read a comic book when he thought-bubbles that he can't see a thing through his hair.
Panel 2: He blows on it to part it but doesn't succeed.
Panel 3: We next see him at a mirror holding a comb and scissors as he tells himself that he needs a trim.
Panel 4: He proceeds to take Elly's scissors and SNIP off a lock of hair.
Panel 5: He looks at the resulting scalping and says that he needs to even it up a bit.
Panel 6: His hands are a blur as he SNIPS and CUTS his hair.
Panel 7: He looks at the result in the mirror (which reminds me of when Adam asked if he was missing an eyebrow) and says to himself "Not bad"; it's at THIS moment that Elly finally appears.
Panel 8: Her reaction is to shout MICHAEL!!!!! so loudly that he does a take.
Panel 9: He responds to her muppet-mouthed wail "Oh, no! Michael" by saying "Dont' worry, Mom...."
Panel 10: "...Daddy says the difference between a bad haircut and a good one is two weeks." She reacts to that by the old smack herself on the forehead in frustration bit.
Summary: Could this happen in real life? You bet!! Should this have happened? Not at all; normal people would have noticed that Mike's hair was getting too long and taken him to a barber. Also, normal people would have impressed upon him that there are certain things that a seven-year-old is too young to do.
