Do you think a lone Extraterrestrial could survive on Earth, undetected by humans?

[AGXStarseed]

If that were true, they would be more accepting of autistics...

Well, the difference here is that Autistics look normal and its only through interaction that the differences become noticeable and can prove disconcerting - like a 'surprise villain' in a Disney movie where you think you know the person but then they turn out to be different and you essentially have to get to know them again from scratch.
In the case of this hypothetical alien (or someone with a physical disability, such as a wheelchair user), you'd recognize them as been different immediately so it would arguably be less of a surprise.

 

[Crossbreed]

Well, the difference here is that Autistics look normal and its only through interaction that the differences become noticeable and can prove disconcerting...

An "uncanny valley" of sorts, then...?

 

[AGXStarseed]

An "uncanny valley" of sorts, then...?

Something like that, I believe. Also, it's not helped by media presentation over the years painting Autistics and other people with hidden/less obvious disabilities in a more negative light - which only serves to amplify that fear.

A person with a physical disability or our 'hypothetical alien', in this situation, would likely still receive some degree of mistrust and prejudice - amongst those who are just curious/want some hits on their social media so they can get a serotonin hit via likes and positive comments - but I don't think it would be to the same degree.

If people think I'm wrong, fair enough - I may be.

 

[Crossbreed]

Something like that, I believe.

"Scary smart" is a similar concept.

 

[GrownupGirl]

Sometimes I think I might *be* an extraterrestrial. I just know my Earth parents found me in the woods next to the smouldering spaceship that crash-landed, and they're hiding the spaceship somewhere.

On the other hand, I think my big brother might have been switched with a space alien when he was around 30 years old. That's why he stopped being obnoxious and annoying to me, and became a kind and caring brother and we get along so well whenever we're together.

 

[AGXStarseed]

Sometimes I think I might *be* an extraterrestrial. I just know my Earth parents found me in the woods next to the smouldering spaceship that crash-landed, and they're hiding the spaceship somewhere.

On the other hand, I think my big brother might have been switched with a space alien when he was around 30 years old. That's why he stopped being obnoxious and annoying to me, and became a kind and caring brother and we get along so well whenever we're together.

In regards to your brother, that makes me think of my own siblings - honestly, I think it's less to do with aliens swapping places with them and more about them getting a dose of common sense and maturity via a metaphorical sledgehammer blow to the head.

As for you getting sent here from another planet, that just makes me think of shows like Superman and Dragon Ball - both of which had the protagonist's parents sending their offspring away to escape their world's inevitable destruction in one way or another:

Superman the Animated Series - Kal-El sent to Earth

Dragon Ball Super: Broly - Bardock and Gine send Kakarot (Goku) to Earth

Mind you, looking back at these clips and going off what you said about feeling like an alien, what if (in a fictional scenario) everybody on the Autistic spectrum was carrying some kind of organic supercomputer in their genetic code (hidden inside DNA that is generally regarded as 'junk'), with said supercomputer working out the calculations needed to save our original 'homeworld' in the past.
It'd be a bit like in the 50th Anniversary Doctor Who episode when the War Doctor (at the time trapped in a room with two of his future selves, the 10th and 11th) inputs a 'subroutine' into his screwdriver that in time would allow the screwdriver of one of his future selves to disintegrate the locked door of the room they're in and allow them to escape.

The Doctors (this time, all 13) later use the same tactic to save their homeworld of Gallifrey from been destroyed by the Dalek Empire on the Last Day of the Time War - safely moving it into a parallel, pocket universe.
If, in this hypothetical scenario, we were working towards that 'long game' goal of eventually restoring our homeworld this way, I could see it happening - even if it is very 'out there':