Round The World in 4 Years

I love reading storys about great expeditions, and this has got to be one of the greatest. Alastair Humphreys has taken 4 years to cycle 45000 miles across five continents. I am so jealous, I dont even have enough time to cycle around Ireland - maybe one day. His maintainance problems put mine in to perspective -

While his machine is nominally the one he set out on, he has cycled his way
through five new wheels, 15 sets of tyres and three new bicycle frames. His
worst record for punctures was set in Bolivia - 15 in one frustrating day;
although the final stages in Europe have not proved plain sailing. Last week in
the Dolomites, he reported "15 punctures in four days, four broken chains, two
buckled wheels, a split tyre, a fragile bottom bracket, no back brake, six
broken spokes in a cracked rim and split hub and only about 10 gears still
working out of 27". - From the Guardian

What an achievement, i'm sure its going to be difficult for him to settle down. There is something so appealing about being continually on the move, maybe its a fear of finally reaching our destination.