J was born in 1965 so he would be about 4 years older than Uma so if it is true that they went to the same school I can see why J didn’t want anything to do with her (I can also imagine that she probably didn’t look good when she was young). However the info I got below says she went to a boarding school. so I bet they just made up a joke when they found out Uma was from Amherst.

from allmovie.com
An actress noted as much for her exotic, almost otherworldly beauty as she is for her considerable
talent, Uma Thurman is one of the most renowned actresses of her generation.

The daughter of celebrated professor of Buddhist Studies Robert F. A. Thurman and Nena von
Schlebrugge, a model and psychotherapist who was once married to Timothy Leary, Thurman was
born in Boston on April 29, 1970. Raised with three brothers in Amherst, where her father taught at
Amherst College, she enjoyed a fairly bohemian upbringing, one that was marked by visits from
Eastern holy men and Tibetan refugees. Encouraged to think for herself and to be independent,
Thurman, who had been interested in acting from an early age, left her Massachusetts boarding
school at the age of 15 to pursue an acting career. Moving to New York, she earned a living by
washing dishes and modeling, though the latter means of support never agreed with her.