You didn't mean to time travel. Sure, you were messing with Booster Golds tech, but you didn't think it would do anything! Regardless, you're in the past and have no idea how the watch you still have on that brought you here works, as it's Booster's future era tech.

You were sat on a dark roof of Star City trying to understand the watch when someone lands on the roof, Roy Harper, aka, your dad, but this is the past, he might not even currently know your mom... You did well hiding until as you were almost on the next roof, you slipped.

"Whoa! Careful, kid!"

Roy grabs your arm before you fall off the roof, pulling you up. Not noticing the similarities between you two yet.