This is a video by Willow Marsden that kind of simulates a bit of what it’s like to be autistic (of course, symptoms and severity vary from person to person). Autistics have a hard time filtering out background thoughts, sounds, sights and sensations; so it’s like being in a television store with every TV blaring out a different channel. BTW she has Asperger’s and is a gifted artist, photographer and graphic designer. Do browse her online store, or contact her if you’d like any graphic design work done. There’s one of her photos below the video, and you can buy prints from her store.
Below is another video simulation of a first-person experience of autism, starring Carly Fleischmann. She has an oral motor condition that prevents her from speaking, but is able to think verbally (and communicate through a keyboard, which is not used in this video). Again, her condition is not typical of all autistics, everyone is different. Having said that, the sensory overload depicted in the video is a common feature of autism.
There are a couple more first-person simulations here and here, both well-worth watching.