How can I tell I am ready for the Solution Architect certification?

Hi, I need to pass the Solution architect certification exam, but I really don't know what I should know . Exam's areas are sooooo wide and complex it almost seems you need to be a cofounder of Sugar to cover all them...

I have seen all the SA webinars and have been developing and integrating Sugar for one and a half year, so I would tell I should be ready. Unfortunately what really scares me is that my colleague, who has much more experience than I do, failed the exam with like 45% of correct answers and said that the questions weren't related to the SA seminars at all.

Any suggestions?