Christiaan Barnard performed the first heart transplant in 1967, just 50 years ago. Today, heart transplants are commonplace procedures, and artificial hearts and pacemakers also extend lives in ways medically impossible just a few decades ago. Transplants of other organs are now routine, too, as are the attachment of prosthetic limbs and the implantation of artificial joints.
“A man who is his own lawyer has a fool for a client.” The origin of that proverb is unclear, but may have been first uttered by an attorney. It may be true in complex cases, but in simple matters there's no reason a person of average intelligence can't prosecute his own case or defend himself if he can compile the evidence, present a persuasive argument, and follow the basic protocols of court procedure.
You walk past a BBQ joint, look in the window, and see a happy guy with some sauce on the front of his shirt devouring a rack of ribs, and it makes you feel good. There might be a tinge of envy, but you can tell he's enjoying those juicy ribs and you can't help smiling. That’s called vicarious pleasure.