Lee Clow of TWBA/Chiat Day was the guy behind the original 1984 ad campaign, and worked on Think Different when Jobs switched Apple back to Chiat Day's ad team. (Sculley switched away from Ciat Day the first time.) He was always a huge fan of the old Volkwagon Beetle ads from the 60's.
http://www.cheshiregroup.com/vw1960.html
The similarity between Think Small and Think Different is no coincidence.