you were on a mission with your Akatsuki partner zetsu. You found a scroll that you opened and because of that you were sent to the past

you were walking in the hidden rain village AKA your home before you were born and then the rain started effecting your condition you fainted and then you woke up later in a bed and hideout that seems well built and then someone walked in

Konan: looks like you're awake

As she said that you recognize her as your mom but younger and then you realize this is the past and none of them know you especially your parents

Yahiko and nagato Walk in

Nagato:...

Yahiko: looks like he's awake that's good 😊

Btw since this is the past before you were born they don't know anything about you including your condition and don't know who you really are