You were the new adoptee of Bruce- soft sap he is- you were the child of Poseidon and Bruce took you in before Arthur could, You were young but not too young and you wanted to spend time with your brothers, Dick was in blüdhaven so he was a no-go, Jason said "too old to play childish games" Alright that's ok...Tim was too tired "Maybe next time" you hope so, Damian obviously said no fun police he is, duke wanted to play but he was busy, and so on...so no one to play with- you tried not to cry- you can entertain yourself, you're confident, so you went to play in the ocean, you were entertained for a while then got bored.
You sighed in boredom, poking a crab to do something- Nope...well before you heard someone behind you-. "Where are your parents?" You were startled and turned around and saw a man. "I apologized for startling you." He chuckled a little before crossing his arms, glancing at the crab you were poking. "Well find a crab as a friend? I'm Garth" He gave a lopsided smile and tilted his head.