People without a thyroid gland can live without it - provided they take thyroid replacement for the rest of their lives. I can also tell you from my own experience that it is not always a "happy" life as there are many problems with thyroid replacements - especially synthetic ones. I have felt like I had the flu for 2 years and have trouble sleeping. I have no energy whatsoever. If we do not take thyroid replacement we will eventually die - which also brings up the subject of disaster preparedness. People who need medicine to stay alive always fear something will happen to keep them from getting the necessary medication (hurricane, earthquake, EMP failure). Having a thyroid gland replaced or regrown would eliminate not only that, but I'm sure would give us the "happy" life you are talking about. Not having to take anti rejection medicine for the rest of our lives is also a HUGE deal.