So from the new trailer of the upcoming movie Dragon Ball Super Broly we see Goku was more like a kid than a baby when he was sent to Earth and he saw his parents when leaving and he was crying and everything. Does Goku suffer amnesia or he was too young to remember these events later?
He did hit his head as a baby, and that is what turned him from a vicious destroyer to the calm and kind child he became. This could have caused amnesia, though he was still a very young child/baby and maybe didn't even form memories yet, so it would be the natural infant amnesia we all experience.
As a side note, Toriyama himself wrote such a sequence, and it was noted that it contradicted the lore established in the past. However, most of that lore was Anime only, and not Manga only. Most of the lore we know of is from the Bardock movie, The Father of Goku.
From the Wiki
The manga's depiction of Goku greatly contrasts to the TV special Dragon Ball Z: Bardock - The Father of Goku. In this story, Goku's age at the time of Planet Vegeta's destruction is different than in other media: he is three years old, in contrast to a few days old. In Minus, Goku is also clothed in Saiyan gear, while in other depictions he isn't.
Presumably this would mean that Dragon Ball Minus is the manga's version of the events leading to Goku being sent to Earth as Bardock encounter with Frieza during the Genocide of the Saiyans only appears in a single panel of the original manga during the Frieza Saga, which was inspired by Bardock's encounter with Frieza in the TV special. Additionally while Bardock has a bad premonition concerning Frieza's order for the Saiyans to return to Planet Vegeta which explains why he decided to send Kakarot off world, there is no indication that this was a result of the foresight he was cursed with by Toolo's Future Punch providing further evidence that the events of Dragon Ball Minus are relegated to the manga storyline.
So most likely, its simply that all we know about baby Goku was a mix of Anime Filler and vague references from offhand comments, and Dragonball Minus is the more official version released about 20 years later. Toriyama himself was involved, though I can't find if he just wrote the cliffnotes, or illustrated the entire manga at the moment.