What do you think Fresh’s childhood (if he had one) was like?
It depends!
If ya go based off AlainaPrana Fresh origin comic on DA.
I'd assume probably really bad, but I'm not sure how canon that still is because it was never finished, but she did mention the original story concept was by CQ.
So going off what was made! and my own ideas of where it could've gone!
in scenario A, I think his childhood was in a lab mostly, I'd assumed that the human have expectations, Fresh was their experiment in some way, so it wouldn't be that far fetched that they might run harmful tests on him, regardless of them being alive and feeling pain, and perhaps having some acknowledge of existence? the human would probably want more acknowledge about him regardless if they knew Fresh was a parasite at that point.
And Fresh first instinct from feeling pain would probably be fear of death, so In my opinion Fresh you know, would react to those badly and perhaps attack the human in self-defense.
So say than the human dies or Fresh takes them as their first host,
Okay but now what? Fresh is new to the world and 'killed' the only other alive thing he knew? They're a strange unique creature, everyone who come across him would be scared, and Fresh would probably immediately get attacked out of fear of the unknown.
And Fresh doesn't have any one to teach them anything, so as CQ mentioned in this post.
Fresh is very naive, probably easily used. which is in my opinion is also implied here-
So It'll make sense that they would start to emulate others behavior to protect himself partly because he learned the hard way to never trust anyone.
But you could go back to the comic with another idea- scenario B, The human did seem really excited about Fresh gaining consciousness, So maybe they acted as a parent figure, and it actually was nice for awhile.
Like maybe they taught him anything they thought would be important for a parasite, (which goes along with him not knowing about sex/love, the human may had thought- why would parasites need to know bout that when they reproduce asexually) but maybe still by instinct from some incident the human died/was used as a host, which brings us back to scenario A ideas.
And you then scenario C, maybe it was a mix of of both the other scenarios.
All three scenarios could also work with why Fresh thinks their better than everyone else, scenario A Fresh only saw the worst in others, and scenario B The human might've acted like they themselves were smarter than others being a scientist and all.
Short answer! I think it was spent in a lab with a human that run experiments on them until the human died/was used as a host, then Fresh had to learned everything in life the hard way from there.
Keep in mind that I probably haven't seen every post about Fresh, so there might be posts by CQ that contradicts everything I just said lmao.