Shiva,
Thank you for your post!
It is true that SAP SD certification is a "theoretical course"!
If the trainer does not have extensive (around 5 years of real time experience as an SD consultant), he would focus on the "memorizing of the configuration steps" without emphazising the understanding of the business (processes etc.) and how to map those in to SAP SD.
Functionality understanding:
Everyday during and after the course, one has to think in terms of the business processes and functionalities.
Needless to say, one has to be a total expert in the configuration steps, the meaning (or functions) of the fields.
Practice intelligently in IDES:
Take a process, the OTC process; map the entire process in IDES.
Repeat the use of various functionalities, related to the OTC process (e.g. Partner determination - what is it? why is it needed?
Account determination - how to set up, for a particular business process?)
Participate in SD forum questions.
This type of intense exercise shall (somewhat) be in line with the "real-time" experience.
And would help one succeed in interviews.