To become a great martial artist!
I don't have sufficient knowledge of Kung fu or TKD to discuss those martial arts styles, but concur with the opinion that genuine fighting practical experience is essential. I've got some kickboxing, I wrestled, coupled with a little bit of Jiu Jitsu. The determining element in a street attack is just not martial technique like your kick and punches as it is so much as the desire to injure and also be injured.
Learn about other martial arts and be like Bruce Lee. Mix your styles: