– Because my history is mixed with Oracle 8 since the year 2000, since when I was a developer with Clipper5 and DBase skills learning PL/SQL for the job and also for my first certification exam.
– Because despite Oracle’s great enhancements and feature additions in the latter versions, the core concepts that drive the software are mostly the same. And you need to be aware and understand these concepts to properly manage the odd situations of the job.
– Because I don’t believe in 2 Day DBAs. I don’t even believe in 2 Month DBAs.
– Because R11.1 is much more complex than R8, with Grid, ASM, Advisors, Automations. Nevertheless, the R8 Concepts manual has 804 pages and the R11.1 Concepts manual has only 556. To your luck, I kept a copy of the Oracle 8 Concepts manual. It’s one of my recommended readings.