My role on the committer team is that of a release manager. We're the folks who actually create the Drupal core releases that you can install on your site.
Back in 2013, I led the core contribution mentoring day at DrupalCon Sydney. I'd already flown from the US to Europe three times at that point (first for Drupal Developer Days Barcelona, then for DrupalCon Munich and the Paris VDC sprint, and finally for a whirlwind 72 hours in London to sprint on VDC and CMI). None of that prior international travel prepared me in the slightest for the over 24 hours of nonstop air travel/physical torture that it takes to get from Wisconsin to Australia.