T-shirt Display

[OLD NINO]

A man walks into a tee shirt store. There are 3 shirts on
display.

The first has a picture of Richard Nixon with a white mustache.
It is entitled - "Got Milk."

The second tee shirt has a picture of Ronald Reagan with a white
mustache. It is entitled - "Forgot Milk."

The third tee shirt has a picture of Monica Lewinsky with a white
mustache. It is entitled - "Not Milk."

[soulfinder]

I don't get it