its nothing to worry about.
just learn as much as you can about the PRMC, RT and Corps in general,
answer honestly, dont swear etc.
for mine, my interviewer seemed content for basic answers most of the time.
you like doing ironing, cleaning, and all that rubbish,
you dont care about going to North ireland, Afgan, Iraq
people spitting on you doesnt bother you
you could make friends with a brick wall if you had to.
if you say you have an issue with a major part of corps life thats a good way to fail i would imagine.
apart from that it was all about fitness, basic knowledge, family, friends etc.