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DF2+R2
I don't like getting into Anime fanfic/theory, but basically the most logical explanation is Broly was almost murdered as a child and so he associates Goku with the trauma of almost being killed and left for dead.Yep that makes perfect sense. He could remember another baby crying when he was a baby even though he was in a pod and had no way of seeing goku. And saiyans sure have the best memories. A bump on the head couldn't be enough to make a saiyan forget his natural born race, or even a half saiyan to forget a appendage tail of his he had for most of his life.
If Broly were to come back I would hope it was a reboot where he's still charismatically insane but with a better plot.