Derek boarded at the College from 1946 to 1950. His father John (OGC 1917) had also attended the College, and his brother Mike (OGC 1950) joined him in 1949. Derek’s interest in music lead him to join the college band, playing the 3rd cornet. He was also a member of the cadet corps, and a keen projectionist for boarders' movie nights. He completed his Leaving Certificate in 1950. 

Following school, Derek returned to the family property, Penrose, at Grenville, where he and Mike farmed for their rest of their working lives.

He maintained a lifelong interest in the activities of the College, particularly when his niece Ros Molyneux became Director of Early Learning, and his great nephews Tom (OGC 2009), Nic (OGC 2012) and Lou (2014) attended the College.