@AkemiDouhito It's not that difficult. Obviously, Accelerator was referring to his ability to manipulate vectors; however, ordinary humans, like you and me, can do the same. It's all a matter of psychology. For example, you may have heard of Izaya Orihara the information broker from Durarara!!, and while he does seem to know nearly everything about everyone he meets, it's sometimes an illusion. His mind tricks come from an extensive, and, albeit, not traditional, training of the human psyche. He seems like a douche bag because he's brutally honest, but will also lie if it serves his purposes. He fishes for material by making a long enough conversation to see if he can hit a nerve, or bring up a memory and get them talking. With this ability, he can easily destroy any human's life. That's something even us, ordinary humans, can do. So, while we may not have an impact anywhere near Accelerator's, he's not wrong, and his words apply to the real world, too.

I would like to have that power :)