Gadget is perpetually high due to machine fluids running through his body
This is a theory I read on the forums, but it makes so much sense: Gadget isn’t dumb, he’s perpetually high off his rocker due to all the machine fluids, oil, etc. running through his body. Just look at his actions: He’s smart enough to utilize an upside-down umbrella as a basket for holding garbage but mistakes a mechanical dragon for a dumpster. That’s not stupidity, that’s drug-induced hallucination.
The catch is that adrenaline can override the drugs and make him “normal” again, which is why he sometimes starts kicking ass (especially when Penny is in trouble): he’s actually his real self during those times. He also seems competent and sane when he’s at home just chilling, in other words at times when he’s not using his machines as much.
‘Current’ Gadget (robot) contains the uploaded