I had a hole of little more than three weeks in between projects and wanted to do something useful such as passing a cetification exam.
So I read Servlets & JSP ²nd edition as well as SCWCD study companion ²nd edition. (this in 15 days time, nine to five) JSP, tags, EL, filters, security... all was new to me.
The day before the exam I studied from dusk till dawn, trying to remember the little details.
There were still some things that weren't perfectly clear to me, but nevertheless I passed it with a score of 76%.
I'm glad I passed it, but at the same time I feel that it was a bit short to really become a true expert on the topic.
But hey, it's not that when you pass an exam, that there's no more reason in getting better in it! I've got the books...