Wishful thinking isn't a bad thing when it works in your favor.
It's not likely you feel better because of just one higher dose, though. Only a minute portion - if any - of the T4 you took this morning was absorbed by your cells. It takes at least 2 weeks for any of today's dose to go to work for you. It doesn't work directly on symptoms the way aspirin does. It works by adjusting the amount of hormone that enters the cells which are then converted to energy. That adjusted amount of T4 at the cellular level is what alters the body's metabolism; the med itself doesn't directly do that.