I never went to a grammar school, just a secondary school. This was admittedly in a rather unique context of 1960s Northern Ireland, whose education system is independent of the UK one. Back in those days, there were Junior, Senior and Advanced Senior certificates, the last-named being the university entrance qualification. Our non-grammar school was only permitted to go to Junior - anyone who wanted to go on had to transfer to a grammar school. The headmaster wanted to do the other qualifications but was rejected by the NI Education Authority. And was that. They thought. They simply hadn't reckoned with the persistence of wee Norman - he couldn't get past them, so he went around them. He went to London University, whose GCE exams were universally recognised, and asked whether he could set their exams. No problem, said London University. And so, the A-levels that took me to Queen's in Belfast are London University ones. In the end, the NIEA threw in the towel and secondary schools were permitted to do the NI exams, which were subsequently brought into line with the UK mainland exams.
And a bunch of kids who really shouldn't have gone to university did so. They included the chief pediatric surgeon of Birmingham's main hospital and the Head of the Northern Ireland Civil Service at the time of the Good Friday Agreement (subsequently knighted). We shall forever be grateful to wee Norman.