Re: a second *binding* referendum and cancel the madness that is Brexit.
If that were actually true, then the Leave viewpoint would have been declining for decades, yet it hasn't. It actually increased to the point where it was carried in a referendum, so your basic assumption must be flawed.
...
is that somewhere in that middle range between "young" and "old" something happens to change Remain voters into Leave voters.
The desire to give the politicians a bloody nose?
From what I saw of the various survey's conducted around the time of the referendum, was a rather significant number of people who regarded themselves as being disenfranchised, saw the referendum as a way of making mischief... Which sort of makes the basic assumption that the vote really was for leave flawed. However, as we have seen the headline result was all the nutters in the Conservative party needed to jump on their hobby horses and go tilting at wind mills.