Many reasons: • Optimism and national pride. "We hold all the cards". EU was expected to give UK an even better deal, because "EU needs the UK more than UK nee

Many reasons: • Optimism and national pride. "We hold all the cards". EU was expected to give UK an even better deal, because "EU needs the UK more than UK needs the EU". • Tabloids somehow managed to make the word "expert" mean "a clueless idiot", so all predictions were easily dismissed as "project fear". • Leave proponents enthusiastically agreed that EU sucks and UK is great. Remainers had mixed messaging like "EU is not that bad", "EU is bad, but we can fix it", "UK is not as great as you think". • Populism. For some the dogwhistle of "securing borders"/"stopping immigration" was more important than anything else.