by mistake / carelessly

外, 他: other, the rest

(archaic) second-person personal pronoun: you

(idiomatic) A piece of cake; an extremely simple thing, something trivial, a cinch, easy as pie.

朝飯前: A piece of cake; an extremely simple thing.

(telephony) a common Japanese telephone greeting: hello; used when answering the telephone / used to confirm that the person being addressed is listening, or to confirm if anyone is listening

put away

human / person / people / individual / man / woman / someone

You'll be convinced if you listen to me.

in the middle of a conversation; on the other line of the phone