Less
Whether you really have respect for R Shach has yet to be demonstrated. However, it seems you must have left a Sefer or two open at some point if you doesn’t know who the ??? is. The ???? ??? is one of the classic ???? ???? that we pasken from.
And no one said forget “all” ones learning, rather it causes one to forget his learning. Any amount of it. Which it is ???? to do intentionally and the psak is that you cannot do action which can cause it.