Hi, i did it last year and yes thats my age! Just go in with the right attitude and never give in on any of the tests, read through the instructions properly and if you can do it twice then do it.
I drove up there a couple of hours early, had a bacon roll and a black coffee to make sure i was not hungry and i was alert.
By the end of the seven tests, which are now the RAF's current pilot tests (which means if you pass and you want to join in the future you do not have to take them again) i was mentally drained and that is how you should be if you give it your best.
If you can fly a flight sim while holding a conversation with someone or answering questions thats as much as you need to prepare, you would be kidding yourself if you try to learn the tests, the idea is to test your aptitude for flying and multi tasking.
I enjoyed it, have fun!
Nick.