When I was a kid I used to spend some time playing boardgames.
One of my favourite was Scotland Yard. I reckon it also contributed, together with Conan Doyle stories, to ignite this neverending fascination of mine for this city.
Anyway, back to Scotland Yard, it is a game of transportation and deduction: the whole point is choosing the right route and getting from A to B faster than X (actually Mr. X, the in-game antagonist).
Well, after living here for 9 monthes, I realized that probably that boardgame is just an over-simplified training ground for London everyday life :)
Try to get to, say, Luton airport on an average sunday morning from south London and you will incur in a random permutation of the following:
. TFL website giving odd results or refusing to give you hint on best routes (I suppose this is like a "bonus stage" of the game)
. Trains being cancelled due to overexcited teenagers pulling emergency brake
. Clueless ticket seller
. No service on the main underground line leading to king's cross (where the train for the airport departs)
. once you get to king's cross: no train connection to the airport (this is like "go back three steps")
. Second bonus stage: find the right bus stop for alternate route to the alternate train station (Kentish Town), under pouring London Rain(tm).
. Oh, unlucky you! There are engineering works in Kentish Town too! No entry from the main entrance. Find the alternate entrance (hint: get around the station, and don't be scared of open wires, jackhammers and so on)
. Congratulations! You are now in Luton Airport: here comes the "boss". Get through the dreadful "security check" and be prepared to surrender your toothpaste! Lucky me, I have no child to milk and don't use lipstick.
This is the story so far... now I'm relaxing in the lounge and waiting for level 2: stay tuned!
Really, this is fun. Life is so good!

Notwithstanding Sunday closures, the best route is No 2/432 to Tulse Hill station and then there is a train all the way through to Luton aiport.
Hope the travel improves when you escape the UK!