There’s a brilliant bit of speculation in the reviews on FF that it’s actually “I’m not Sirius”. Makes sense to me, I was trying to imagine what “worst memory” would prompt “I’m not serious”. Although now that you mention it, a guy like the Joker might end up that way.
If I remember correctly, the non-patronus Fawkes also lingered at that cell, which would make sense if there was an innocent trapped in there in place of Sirius.
There’s a brilliant bit of speculation in the reviews on FF that it’s actually “I’m not Sirius”. Makes sense to me, I was trying to imagine what “worst memory” would prompt “I’m not serious”. Although now that you mention it, a guy like the Joker might end up that way.
If I remember correctly, the non-patronus Fawkes also lingered at that cell, which would make sense if there was an innocent trapped in there in place of Sirius.