Should Gherkin 'Then' statements refer to 'I'

I've been using Gherkin (with Cucumber) for many years now. I noticed early on that Cucumber.io homepage examples refer to 'I' in the given and when statements, but not in the then statements.

I always assumed this was because given and when statements are subjective actions by a user, where as then statements should be objective measures about the state of the application under test.

However, I noticed in the official Cucumber book, their examples refer to 'I' all the way through the steps (including when using then statements).

Anyone know which method is correct?