I didn't make my claim lightly. http://origins.osu.edu/history-news/getting-wrong-lincoln
The quote is a fine quote, and coincides with my own sentiment. Still, I have never very cynical of much that Is spread around the internet.
Snopes has a good explanation on why the quote was included in the Lincoln Encyclopedia, for example. You can read the incident on their site.
I'm glad you didn't outright attribute it to Lincoln. The picture hints at it, but then, a lot of people have been fooled since those days. Believe it or not, I'm not trolling you. Before I switched to humor, I'd studied journalism, and learned the hard way to keep the premise of my humor somewhat on par with reality. I could use this in a speech, saying that, while falsely attributed to Abraham Lincoln, the original author is unknown. Why he chose Lincoln is fairly obvious: he had something important to say, but knew if he attributed it to himself, nobody would pay attention. But to say a great man said it: people would listen.