What did “your mom did a number on you” mean in Seinfeld?

Question

I remember one episode on Seinfeld, a girl said "did your mother do a number on you" when they were talking about breaking up or not.

This is the sentence reported from the transcript:

LISI: Boy, did your mother do a number on you.

According to Urban Dictionary, its meaning is "treat harshly or damage."

What does that mean, in that context? Did Lisi mean that Seinfeld did not dare to fall in a long term relationship because he had bad childhood memories (his mother treating him badly)? Why is it "do a number on"? (why "a number" and what does "do a number" literally mean?) Which is its origin?

Answer 1

The statement "your mom did a number on you" is a disparaging remark usually said by women who find some kind of flaw in the men with whom they have a relationship. The flaws may range from the man having an inability to commit to the relationship, a failure to have matured sufficiently (because of the overprotectiveness of the mother), or some other related issue.

It does not necessarily mean that the man had bad childhood memories. It's more of a commentary by a woman on how the training given by another woman (the man's mother) has unsuited the man for a proper relationship with an adult woman.

Answer 2

The implication is that Jerry's experience of being brought up by his mother has left him damaged to the extent that his upbringing is causing him to make misguided decisions about the relationship he is in now.

Also, though used in dealing with Jerry's mother doing a number on him, the context of the saying is not limited to mothers doing a number on someone. Anyone can "do a number" on anybody.

As far as its origins, the OED attributes the expression "to do a number on" to have first appeared in print in "The Unbelievable Dictionary of Hip Words (for Groovy People)" in 1967. It is a colloquial expression that has its origins in the African-American community.

Answer 3

OED’s first print citation is Hy Lit’s unbelievable dictionary of hip words for groovy people (1967), which defines do a number as “to get mad; make a scene; to tell somebody off; blow your cool”.

This is likely a figurative use of the show-business idiom do a number meaning “perform a stage act”. (Compare make a scene.) OEtmD traces its origin to the printed performance bills for variety shows in the late 1800s, on which each act was marked with a number. (For an example of such a bill, see the “Vaudeville” entry in Wikipedia.)

But OED adds that do a number (on) has acquired a more general meaning over time: “to act with destructive force or impact; to criticize or humiliate; (hence) to have a strong, usually adverse effect”.

Consequently, the excerpt in question means that Lisi blames Jerry’s mother for damaging him emotionally, thereby contributing to their relationship problems.

The idiom does not imply that Jerry suffers from a specific kind of emotional disability such as fear of commitment. The montage scene is simply a collection of statements that are stereotypical of lovers’ quarrels. The scene implies that Lisi and Jerry absurdly spent nine hours playing out every possible lovers’ quarrel stereotype. The humor of the scene derives from this absurdity.

Answer 4

This idiom is commonly used in situations where a relationship has gone sour. For instance:

• John did a real number on Katy Perry.
• So Mandy really quit her job. Boy, did I do a number on her or what?

So, in plain simple English it is an equivalent of

• treating someone like shit

or

• f——king with a person’s brain