Yes, that is why the simplified ones are so formed I guess. The original right sides and the "simplified" ones have no relation. They just switched them with the same phonetics. There is nothing common between 忍 and 人 except their pronounciations.
One means to be familiar or be acquainted with, the other is to know like knowing something or having knowledge about something. You know about a road but being familiar with it may imply a more concrete, more profound level of knowledge.