Lance corporal
De Grave attended a Gymnasium in Assen from March 1967 until May 1973 and applied at the University of Groningen in July 1973 majoring in Law and obtaining an Bachelor of Laws degree in June 1975 before graduating with an Master of Laws degree in July 1979. De Grave was conscripted in the Royal Netherlands Army serving as a Lance corporal from October 1979 until November 1980. De Grave served as Chairman of the political youth organisation Youth Organisation Freedom and Democracy (JOVD) from June 1978 until March 1980. De Grave worked as a political consultant for the People's Party for Freedom and Democracy from November 1980 until September 1982. De Grave served on the Municipal Council of Amsterdam from April 1982 until September 1982.