you're day to day life as a pilot, you only need to remember about 0.1% of what was shoved in your head at ground school. once you sit and pass the exam, you have a brain enema and forget everything you learnt so you make space for some new stuff.
honestly, who needs to know the spacing between approach lights on a calvert lighting system? has any professional pilot argued the toss with some dispatcher over the chicago convention? nope. 99.9% of what you learnt is irrelevant. obviously it's always a good idea to hang onto your books if you are a pervert that needs to look that kind of stuff up.
fortunately, all the stuff you will need to remember from ground school has been conveniently condensed into the Part A of an Ops manual.
as for interviews, things you should prepare for.
a) a basic knowledge of the aircraft and company you are being interviewed for.
b) answers for the usual pseudo-psychobabel 'where do you see yourself in 5 years' questions that guardian reading huggy fluffs like to ask.
c) prepare using a technical interview book for an idea of general aviation related questions you maybe asked. although these books can be at best misleading, and at worst downright wrong, it does get you thinking on the right lines as to what's worth knowing.
d) clean your suit, brush you hair, shine your shoes, smile when introduced and have a firm handshake. the rest will be easy after that.