The Nightwatcher seems confused as to why anyone would ever want this, but obliges. You can taste any taste, feel any feeling, feel anything, smell any smell, or see any thing at any time, but unfortunately you can't stop tasting every taste, feeling every feeling, feeling everything, smelling every smell, and seeing everything. Your bane is immortality and immunity to insanity.
I wish for the ability to play any retro game that I want.