I played almost 71k hands at NL2 and my winrate is 18.94bb. I put in Primedope variance calculator for real winrate 10.15bb and for observed winrate my current winrate at nl2. Primedope says that the probability that my winrtate in 71k hands is at or above 18.94bb is almost 1%. So this means that if we somehow knew that my real winrate was 10.15bb, 99 out of 100 times I would be below 18.94bb winrate in 71k hands. Since I am not below that winrate this means that we can say with 99% accuracy that my real winrate is above 10.15bb.

Is this a correct way to think about my winrate? We can't obviously know the real winrate unless we play 1 million hands(or as much hands as it's required anyway). However, I think this way of thinking is good to know where at the worst case scenario my real winrate is going to be.