I majjin - You say 'I majjin' when you think someone's guess about some

You say 'I majjin' when you think someone's guess about something dumb sounds like it might actually be true.

'You think the cat knocked over the lamp?' 'I majjin.'

'You say the kid in front of you is gonna fail the test?' 'I majjin.'

'You think the teacher is going to yell at us again?' 'I majjin.'