If you felt fine before the surgery, no hyper or hypo symptoms, those labs would be considered your
"normal". Use those as your baseline for possible thyroid replacement.
If you start having symptoms, have your TSH, FT4, and FT3 (if you can get it) re-checked. If TSH is markedly higher and/or FT4 lower, that means you need additional hormone. It could eventually happen that your gland will "catch up" and start producing enough hormone for your full needs. Should that happen, there may no longer be a need for additional hormone.
I can't believe you were able to web-surf the day of surgery! You wouldn't fib to us about going through with it, would you?
Seriously, you're a real trooper. Heal fast and be well.