Board Thread:Anime/@comment-36552187-20180913104607/@comment-24850639-20181003181105

I get the OP's point. There's no real reason that Levi shouldn't know that his family name is Ackerman. Especially considering his shock at hearing Kenny's last name, the shock itself implies that Levi was aware of this last name being identical to his own.

Furthermore, Mikasa gets assigned to his personal squad. There's NO WAY he wouldn't be given the full names of all his newest squad members. Him remembering them all may be another thing, but he for sure had to be told them at least once. And even at that point, it should have struck a chord that Mikasa's last name was Ackerman. And this is before even factoring the whole "burst of power" portion of the argument into the equation.