Recently Donal Larson wrote:
 
A last thought on COLLEGE:
This film has the weirdest ending of any comedy I've seen, yet critics seem
to scant it.  At the end of the film, Keaton rescues the heroine from the
campus jock and the two walk to the campus chapel to get married.  Normally,
that's where one would expect the film to end.  But then there's a dissolve
and we see the two in a kitchen surrounded by children; then another dissolve
and we see two old people in rocking chairs speaking sharply to each other;
then a dissolve and we see two gravestones.  Moral: They didn't live happily
and they sure didn't live ever after!
 
You are correct:  it is one of the more unusual images found in film during
that era.  It is an unforgettable one. Keaton was known for his surrealistic
perspective as well as his unhappy personal life.