My tsh is 55.0- how come I dont have any symptoms?

Slippery slope. Perhaps you didn't notice b/c slippery slope phenomenon. Anything greater than 4.5 is abnormal but would you notice any difference at 5? Or 6? Or 7? Or 10? Or 20? Maybe it's been slowly declining over time. Like take stairs down high rise rather than elevator. Or may just be lab error. If you really aren't convinced enough to take medication, ask to repeat test. After all, we're here to treat you.