People don't often understand chronic pain - they think they do, they've dealt with pain, but generalizing from an ache and pain here or a headache there to pain being a constant part of your life, that it partially shapes your life. This pain isn't just there, its constantly there, and its not only constantly there, its what determines what life you're living.
The thing about this pain - this pain that is constantly there - or at least one thing, is that you can't stop for it. One of the privileges of not having chronic pain is the ability to stop because of pain, and it being the proper thing to do. When you don't have chronic pain, its not only acceptable, it is appropriate and right to stop when you've pushed yourself so far that you're hurting. It is wrong to keep going when you've caused pain when you can set it aside and finish it tomorrow, unless its extreme circumstances.
When there's chronic pain, you don't have this luxury. You don't have the option of stopping because of pain. You don't have the option of saying it hurts today I'll do this tomorrow, because it hurts tomorrow too, and the day after that, and so on. There are questions of trying to manage pain, and trying to not overdo it, but pain is no longer an excuse, pain is no longer a reason to stop going today unless the pain will be unmanageable tomorrow, pain is no longer a reason you can say that you can't do something now.
When someone has a bad headache they can take painkillers and say they can't do the grocery shopping today. When someone with chronic pain has to do the grocery shopping, they need to do the shopping. They might rearrange what they are picking up so that they're walking the shortest path, or such that they're not carrying any heavy items, but they still need to eat. Pain is no longer a reason to put off the shopping.
So, when it comes to abnormal sensory processing, the same types of things hold. Except that most people don't ever even get the headaches in the first place. Most people don't even get the equivalents of twinges of pain. They don't need to say that things are too much, they don't need to say they can't cope with things, they don't need to find to ways to cope with things that are going on around them. They never feel pain, except they never get any of the downsides of not feeling pain.
And then there are some people who have to cope with headaches and aches and pains. There are people who if you push them to far, or if they push themselves too far will respond with pain. They will sometimes wake up in pain without a good reason, and will need to react with pain killer equivalents and saying that today they can't do the grocery shopping. We need to be accepting of this. We need to let these people do what they need. These people are the equivalents of people who get headaches in a world of people without pain receptors.
Except, there's a level above that as well. There are the people with chronic pain. There are the people who no longer can say no, I can't do that today. There are the people who have to just keep going even though it hurts, even though the world is at constant war with their body and their body is at constant war with itself. They no longer have the option to say its too much, because its always too much, or that its not enough, because its never enough, or that its not right, because its never right. They always have to fight to make it as best they can, and as best they can is always still pain, and always still more than most people deal with, or can ever imagine dealing with.
These things affect people, and the lack of understand can too. Treating people right matters a whole lot. Remember that people can't always say no. Remember that not saying no doesn't make it easy. Remember that these people who are saying that their bodies are processing things differently mean it - when they're saying that it hurts and they can't take it today that they mean it, and remember that those of us who no longer can say that and who have to just try to grin it and bear it and the chronic pain it causes have to do that too. Please.