“The days when you are exhausted and on the brink of quitting, remember why you started. Think about all those people that are relying on you. You may be an inspiration for a lot of people without knowing it.”

On Leon Trotsky Saturday Evening Post (6 November 1926) - note that Rogers specifically spelled the word "dident"
Context: I bet you if I had met him and had a chat with him, I would have found him a very interesting and human fellow, for I never yet met a man that I dident like. When you meet people, no matter what opinion you might have formed about them beforehand, why, after you meet them and see their angle and their personality, why, you can see a lot of good in all of them.

Source: Darkly Dreaming Dexter

Not located in Edison's writings, but found in Robert H. Schuller's self-help book Tough Times Never Last, But Tough People Do! from 1983 https://books.google.com/books?id=8oTOa4n3k4oC&pg=PA28&dq=%22exhausted+all+possibilities%22+remember&hl=en&sa=X&ved=0ahUKEwiL88bb6-vKAhVD-mMKHVzNDVEQ6AEIHTAA#v=onepage&q=%22exhausted%20all%20possibilities%20remember%20this%22&f=false.
Disputed

Variant: It's quite an undertaking to start loving somebody. You have to have energy, generosity, blindness. There is even a moment right at the start where you have to jump across an abyss: if you think about it you don't do it.
Source: Nausea (1938)
Context: I know. I know that I shall never again meet anything or anybody who will inspire me with passion. You know, it's quite a job starting to love somebody. You have to have energy, generosity, blindness. There is even a moment, in the very beginning, when you have to jump across a precipice: if you think about it you don't do it. I know I'll never jump again.

Source: Only Love Is Real: A Story of Soulmates Reunited

Source: Memnoch the Devil

Interview in The Guardian (18 August 1989)

Source: Only the Good Spy Young