The thing I can't stand is when subject material is presented as a collection of facts to be memorized. Teachers who do this are the worst. I particularly find this format challenging as I have very poor memorization skills. Instead, I must thoroughly understand the theory or concepts which produce the facts to be learned. When asked to recall information, very rarely do I actually remember that information, but rather I resynthesize it rapidly from conceptual understanding. For example, I can never recall a particular rule or theorm in calculus unless I thoroughly understand the proof. At that point, in my mind, the theorm is then implied by existing understanding rather than memorized without base.
I struggled a lot in school and it was rare that I came across instructers who could really reach me. I became really adept at teaching myself things on my own time. I later quit college and taught myself to be an electrical engineer and I now design medical equipment for a living. I still have a love for learning though and have made it my passion to constantly acquire new skills through self exploration. I guess if there is a point to my rant, it is this: We are individually responsible for our own development. If you find the way a subject is presented difficult, then take it upon yourself to try other approaches on your own. If you find one that works for you, it will be worth the effort.