I actually did meet Stallman on a few occasions. In all cases he was a kind and generally awesome human being:

  * 2000's, Linux Conference in San Francisco / Silicon Valley, I asked him about porting some app from LibC5 to GlibC6, I bought the GNU LibC manuals there. I imagine he was more confused than me about my newbie questions, but he patiently heard me out and gave me some valuable insights.
  
  * 2010-2016ish, FOSDEM conferences in Brussels. Attended multiple talks of him about FOSS.

Edit: Small spelling fixes and clarifications here and there.