What sorts of materials came with the course (i.e. did you get any paper, books, to take away?) I paid for one of their courses a few years back about how to service your boat where they come and show you how to service it - but the problem was that while I felt confident at the time, when time came for the next service, I'd forgotten a few bits and bobs (and had a very irritating few hours trying to work out why, despite priming my engine, etc, it wouldn't start - I'd left one of the two little o-rings that come with the fuel filter on the engine)
PS - replies telling me I'm a moron for making such a simple mistake not required - I know already!