A student well versed in even one technique will naturally see corresponding points in other techniques. A upper level punch, a lower punch, a front punch and a reverse punch are all essentially the same. Looking over thirty-odd kata, he should be able to see that they are essentially variations on just a handful.
Karate-dō Nyūmon: The Master Introductory Text (ed. Kodansha International, 1994) - ISBN: 9784770018915