Expect greatness.
The man in a wheelchair does not want your silent condolences, he wants you to look him in the eye and engage. The HIV positive man does not want your mournful laments of his condition, he wants a clear assessment of his abilities.
To project deficiency on our fellow human brings him down. Do not yield to the temptation to placate the challenged. Instead, respect the diverse gift of their experience and expect great things from them.