History moves on. Each generation has issues of its own.
Do you know what the Corn Laws were and why people on both sides of the debate got so angry about them? No, neither do I. I looked them up once and then promptly forgot what I'd just read because none it touched me where I live.
As Eliot wrote of the sides in the English Civil War;
These men, and those who opposed them
And those whom they opposed
Accept the constitution of silence
And are folded in a single party
And so it will be with Brexit.