That's nothing more than common courtesy, really. Try not to make stereotypical judgements about the abilities of others. Remember that a physically, visually, or hearing challenged person's problems are most likely not related to cognitive skills. Don't assume they know less than you do. If people regularly levitated and zoomed around, they might call you disabled for using your legs to move.
Disability is relative.
Don't call disabled people courageous just because they're doing things you might not have the motivation or inclination to do. It feels patronizing. Most of all, just try to be a caring human being. If it looks like someone needs help, then offer them help whether they're disabled or not.