Ahhhhhhh what enjoyment I've just got out of reading through this giant topic.
I've just got one thing to say - and this is not to offend anyone just a point that I'd like to make - :
Its very easy to tell which guys on here have spent too much time at uni with their head in a book looking at everything from a scientific, theoretical, complicated technical viewpoint.
Then you have the guys who are QUALIFIED tradesmen with years of "hands on" experience, knowledge and know how, skinned knuckles

, chasing intermittent problems under pressure while listening to someone tell them they know a guy who done that in 5 mins whats taking you so long etc etc ##$@ etc................
You could spend an eternity at uni doing degrees in mechanical engineering or whatever but it can NEVER teach you "HANDS ON EXPERIENCE"
So get a spanner in your hands and get a feel for it because sometimes I think you can actually be so smart that you're stupid