Here's an example:
I found this to be an interesting read: http://www.billzilla.org/engineintro.htm
Plan is to invest in a cheap/modest twin cam engine (4AGE,SR20DE,G13B) and pull it apart and learn it back to front. Not planning on becoming a mechanic or opening a performance shop

Knowledge like this should definitely help in the longterm as I have a few projects in mind for the next few years, hoping to get started once I settle into a stable work situation (have lots of free time at the moment). Main thing in mind includes an fto track car for open class or hillclimb (still looking into it). Not sure how much modification is allowed in these classes but even if they're not allowed then being able to carry out my own maintenance and recondition work would be good.