As mentioned in the article, this is just an adapted snippet of the full Kenyon College commencement speech in 2005. You can watch the video of full speech (which I recommend over the text version because Wallace' intonation makes the whole thing feel a lot more light-hearted and palatable without losing any of the sincerity or meaning) here:
https://www.youtube.com/watch?v=8CrOL-ydFMI
It's well worth your time.