Occasionally there is a silver lining to a slow economy. Within a technical training company it is common to allow instructors to cross train by sitting in other classes offered by the same company for little or no cost. There is usually the expectation that the class is either one that the instructor may eventually teach or at least a related topic that will enhancing the instructors ability to teach the classes they already teach. For the full time trainer it may be a job requirement. For an active contract instructor it is usually more of a courtesy if a seat is available - and with the right to bump the trainer in favor of a last minute paying customer.
Over the years I have had the opportunity to sit in a few classes for the "cost of materials" and many classes for "free". I do not get paid for the days I spend learning instead of teaching. I also pay for my own travel but I have been very lucky to live in such a technology rich area that I can usually find a local offering. Long ago I had many students attending Intro to Linux classes ask "is that like the Cisco IOS?" When I had the option to sit in a CCNA class I took it and refreshed my memory on telecommunications while I learned a little bit about the Cisco IOS. By the way, there are several similar commands between the IOS and Linux and other Unix command line interfaces.
This spring one of my clients suggested that I cross train with the intent to teach some of the AIX curriculum. The first step is to sit in the classes. The admin class is running at the local training center this week and I am sitting in class. There are a lot more differences than I remember. I worked on AIX some in the early 90's. It still looks the same. To be fair, we are running an older TL of AIX5.3 right now so I am trying to reserve judgement until we upgrade to the AIX 6.1 later this week. Linux on the other hand has moved ahead in leaps and bounds. As much as I get frustrated by some of the bloat in some Linux distributions, overall it so much more flexible to configure.
I do not know if I will get far enough to teach this course. There are a couple other courses that go with it to have all the knowledge for any type of certification. I would like to continue the cross training, but even if that does not happen this will help me teach Linux and I already think it is worth the cost to my sponsor. I have a lot more sympathy for my students transitioning from Unix to Linux. Sure find, grep, and man can get anyone there but when you have to remember to add the path to find and work with a grep that doesn't have the --color option it does get a little harder. :)