What tech was way ahead of its time?
Electric automobiles. Not quite ready to take on the internal combustion engine for most of their history, but their time is likely arriving arriving soon, only 120+ years since they arrived on the scene.
I would have to agree! My next car whenever that will be will definitely be electric.
I can't think of anything that comes close to this answer.
The Nimrud lens, the earliest optical lens found yet, is believed to be made in 750 BC. It may be the earliest magnifying glass.