I can't stand the bloke, but there's no denying Johnson has charisma. If you're not really bothered about politics, only pay it passing interest, then I can easily see how people were taken in by him. I only really started taking an interest in politics when I started working on ministerial briefing in the Department for Health. Think I probably thought Johnson was harmless and entertaining before then.
The real test is what you do when you do realise what he's like. When you have all the facts. Not an easy thing to hold your hands up and say "I got it wrong". There's been psychological studies on it, it's human nature. Most of us are very resistant to it. So fair play to you.