I do some stand-up comedy and people find my lack of delivery funny. It's not intentional on my part, just my way of talking.
When people see me on stage for the first time, they often come to me after the show to tell me it's a great character I play. At which point I tell them I was NOT acting, and they assume I'm pulling their leg and I'm still in character.
I once did a show where I was convinced I did a good job at doing voices, accents and emotions, put a lot of hard work into it, but when I watched the recording someone made of the show afterwards, it all sounded the same, no delivery at all. Quite weird.