I want hard Brexit too. I want to see an end to freedom of movement for EU citizens and everyone wishing to enter this country being given a level playing field as far as entry requirements are concerned.
I want to see us get the best deal we can when it comes to trading with the EU.
OK, so fast forward 10-15 years. The EU immigrants have stopped coming so the NHS is short of staff. So - either the NHS has to cut back severely or they are replaced by other immigrants, most likely from Africa and the Indian sub-continent. Fine, this is what you want, but do all your fellow Brexiters want either of these options? I think not given the increased racist attacks directed at Muslims, and I think a relatively small number of EU migrants are Muslim.
Then also, in the agricultural areas, they can't get the staff to come to pick the crops, so the firms migrate elsewhere, and we need to import more food, at greater cost.
OK, then the EU says sorry, no dice. We gave you a good deal, and you threw it back in our faces, you have spent 40 odd years bellyaching, so you can trade with us on the same terms the rest of the world outside the EU. So cost of goods go up. Then Nissan and BMW say that it's no longer economic to have major facilities here so pull much of their business out.
Then the white commonwealth says 'why should we offer you good trade deals? You shafted us last time, we have now found new markets'. So no rushing to do deals with them.
Then the developing economies BRIC. Brazil at the moment is in trouble, Russia, well, that's a bit of a no-no, China we have just insulted, but India should be OK.
The Scots and Irish are P'd off, and may or may not go for Independence.
So you are part of a small impoverished island, which has trade but its expensive, many of the service industries have collapsed. So the tax revenues have collapsed.
You have taken back control, although you still have to abide by the regulations of the countries you wish to trade with, but have no say in their laws, so your sovereignity is a bit illusory. You won't have the easy whipping boy of the EU to complain about.
If that's the country you want - fine, but don't come complaining that it wasn't what you wanted.