I know a couple of OG hippies (they went to the original Woodstock), and they are some of the angriest people I have ever met.
Most of that shows through in their intolerance. Usually for new things... intolerance for new types of music, experimental television shows, etc. I chalk that up to them being old, but they will fucking scream your head off if you're playing something like Opeth... even if it's in your car and you're giving them a ride!