I was in India with AV for four months in 2008.
Though some time has lapsed since then, some things still stand out. In particular, I met two of my best friends there, who were in the same group as me (we shared a room).
The food is some of the best you will ever taste. We cooked all the time and I still make curries at home using lessons I learnt there ('the key to North Indian cooking is jheera-dhanya').
Teaching is hard, but it is fun playing with the kids in the playground and your work is appreciated by the teachers.
The landscape around Darjeeling is beautiful, and a slightly easier climate than on the plains. The tea plantations stretch for miles and are unlike anything I have ever seen before or since. The trek we did in Sikkim was unforgettable - lush and green at the bottom, getting sparser as we rose. When we climbed to Kangchenjunga base camp at the peak of our route, the sunlight broke through the clouds, to reveal peak after peak. It was one of the hardest, but best experiences of my life.
The AV support network is impressive - I'm sure as much so for parents as gap year students - and in particular Tendup Lama and Richard Venning had invaluable local knowledge. My friends and I attend the AV Carol Service on Farm Street every year, which always makes for a great evening and attracts quite a crowd.
In all, you may have moments in India when you think - your feet are tired, your room is damp, you want some cornflakes. But acclimatising to local life; the smells and sounds; the language and clothes - even the very strange loos - these are the experiences you will never forget.