//...is there any evidence we are wrong?//
Well, Peter, that depends. I'm neither ignorant nor a racist. I voted to Leave. So with respect to me at least (and I doubt I'm alone) you are indeed wrong - very wrong.
//The negatives of leaving will fester on and on...//
That, of course, remains to be seen.
//...until we get a government which sees sense and begs to rejoin the EU.//
There is no way any political party in the UK which stands on a manifesto of applying (let alone "begging") to rejoin the EU will be elected to office. In the last election the so-called Liberal Democrats stood on a platform of cancelling Brexit unilaterally and immediately. The SNP said it would push for a second referendum with "remain" as an option. Both gave those voters wishing to remain a clear choice to see a Parliament which reflected their wishes. They polled 15.5% of the votes and gained 9% of the seats between them.
The EU will have disappeared up the backside of one of its own obnoxious Directives long before the UK begs to rejoin.