I might have read too much into it, but it’s easy for readers to extrapolate to “if you become more optimistic you’ll live longer”. A parallel would be to read

I might have read too much into it, but it’s easy for readers to extrapolate to “if you become more optimistic you’ll live longer”. A parallel would be to read “people who wear XXL are more likely to be fat”, where forcing to wear a smaller size won’t make them thinner.