[Oh, yes, thank you for the pen. He starts jotting out a quick, capslocked note TO WHOM IT MAY CONCERN, since it's meant for any friends that find it.]

They're very motivating! Knowing, first hand, what it would be like... if my brother didn't know me... [Not just didn't know him. But if Sans was angry, and scared, and so out of sorts that he was openly shoving things around instead of hiding in his room...] If I had any doubts about helping, remember that dream cleared them up!