I even voted against the EEC in Harold's day too ...
Interesting comment and indicative of the voting demographics in 1975 and 2016.
There is a lot of guff talked suggesting that because in 2016 it was the young that voted predominantly to remain, and the old that voted predominantly to leave, that 1975 was the same. The inference being that those who were relatively young in 1975 voted to stay in the common market but changed their minds by 2016.
But analysis of the 1975 demographics doesn't back this up. In 1975 the least likely group to support being in the common market were the younger voters, while older voters (probably those who remembered and were affected by the war) voted heavily to join the common market.
So in fact those young anti-common market voters of 1975 became the old brexit voters of 2016 - they hadn't changed their minds at all - they were against in 1975 and remained against in 2016.