"I know myself."
Translation:나는 내 자신을 압니다.
Taken from Duolingo Tips & Notes: Definitely yes. 저 is for lowering oneself, and -ㅂ니다 is for raising the listener. If you are higher than the listener, you can raise them by using -ㅂ니다, but you don't have to lower yourself. On the other hand, it is weird to lower yourself and at the same time not raise the listener.