>>1 OP we have already a very long on going Martial arts thread, use the view all threads button next time before making a thread that we most likely already have.
here is the link to the on going Martial arts thread - copy and past -
http://dollars-bbs.org/sports/res/1310869733.html
And to you're question it really comes down to how good your taekwondo instructor/master is because like anything some people are good at teaching and some are bad at teaching, and a good part of it comes down to you and how dedicated you are in your own are training.
Also just to add there is not just one style Tae Kwon-Do out there, I,e -
International Taekwondo Federation ITF
World Taekwondo Federation WTF
Rhee taekwondo
and some other groups which may or may not be connected to them main groups