If you are studying Muy Thai you should study everything!!!! The differences I've seen between traditional teachers (usually from Thailand) and Western teachers are extreme. The traditional teachers insist on respect first and foremost. Respect for the culture, the technique, the gym and the master. The western teachers usually only care that you pay them on time. If you are going to dedicate so much time to an art form you should really know what the heck you're learning and why.