Here is my own little (incomplete) Top-10 list of favourite pasttime achievements:

  1. Experiencing the birth of my amazingly cute baby boy Oliver.
  2. Being expedition scientist on the Tycho Brahe Expedition 1998 to Greenland where we searched for the famous Greenland meteorite. Read one of the diaries or Wayt Gibbs nice article in Scientific American. See also a few pictures here.
  3. Running the Copenhagen Marathon.
  4. Jumping out of an aeroplane (and surviving)
  5. Participating in the Kap York Meteorite Expedition 1994. This expedition inspired (in part) Peter Høeg when he wrote his famous novel Miss Smilla's Feeling for Snow
  6. Doing the Overland Track in Tasmania in 3.5 days (in the winter)
  7. Climbing the highest mountain in Germany, Mt. Zugspitze three times
  8. Winning the prize for the school's best exam in 1989

...room for more fun :-)