1) David Cameron came up with the referendum idea because he was sure that he could win it and because he needed a tool in his fight against Conservative leadership rivals who were beating him up on the EU deal and immigration. Cameron resigned because he had made an enormous blunder by playing a political game to try to cement his authority.

2) The current PM, Theresa May, was supposedly on the Remain side during the referendum campaign but is suddenly the Leaviest of the Leavers - what's that about? Boris Johnson campaigned hard on the Leave side in order to challenge Cameron for the leadership but is believe to be on the Remain side. The government benches were a full of dissemblers on Brexit - it was all politics and had very little to do with what was good for the country.

3) The referendum was unnecessary and is non-binding so the real question is "Why is the British government blowing the country's economic brains out over internal Conservative politics?"