updated from 30 to 70 decibans: I would more easily be convinced that I had won the lottery than that this wasn't so.

I might be misunderstanding what you mean by 'more easily be convinced', but if the nature of the evidence we'd expect to be doing the convincing is so different in each case, I don't think we can rely on that to tell how much we believe something.

I was much less easily convinced about Many Worlds that I would be that I'd won the lottery, but beforehand I think I'd have put the odds about the same as rolling a six.