This is only an idea, put online so the idea doesn't get lost, I am not going to expand on this.
An unexpected reunion
What if Android 17 & 18 were actually the same age as Gohan?
What if Gohan met them along with the other orphans while he had to survive alone in the wilderness for half a year before the other Saiyans showed up?
What if they got to know each other (well) and Gohan gave a self-made necklace to 18 to remember him by before they separated?
What if Dr. Gero, in order to prepare them for the experiments, put them through an accelerated grow process?
What if Krillin was the one to take Bulma, Trunks and Yajirobe away, so Gohan had the Senzu beans and was present when 17 and 18 were released?
What if Gohan noticed the necklace and in turn 17 and 18 recognize Gohan as the boy they met years ago?
What if they then all team up when Cell from the other timeline shows up?
Eventual Gohan x Android 18 pairing maybe?
People who want to write but lack inspiration grab your chance! Just put my name as the person you got inspiration from in the summary and we call it even :)