My glib answer would be that maybe the 67% thought that by staying in, it would give another £350m a week to the NHS.
My main point though is that by trying to dupe the people of this country, the establishment will always be found out.
I think the worst decision this country has made in modern times was not to have a referendum before we were taken in to the 'EEC' in 1973.
It has lead to 40 years of lies and obfuscation by the political establishment class and 40 years of distrust and cynicism by the electorate.