Certificates, in this sense, are (for the most part) badges that show your effort at obtaining an elevated operating level in Revit. I say effort, because that is truly what it is. The actual success in Revit (or any program, for that matter), is seat time. Seat time. And again, MORE seat time. Borrow an old set of plans from someone, if you can, and run completely through the jobs, as if you were producing them for a client. Down to inserting a logo into the title block, and actually printing a project. Do it a couple of times, as suggested. Then is when you will find your shortcomings, and the areas in which you need to improve. Certifications and testing are good, to a point, but to be able to whiz around within Revit, seat time on real projects will benefit you far better than a certificate. I, too am a Revit Certified Professional, and I did it for the same reasons that Harry C. did it; to prove to myself that I had the pedigree.