I'm a retired design engineer. Our company built truck-mounted drill rigs used for water well and closed loop heat pump boreholes. I used to know a lot about power hydraulic systems, but that knowledge fades a little more every year since I retired in 2012. 

Like most of us, i had trains as a boy and now that I'm a boy again, I've been easing back into them. So far all of my equipment has been Lionel Legacy. 

I suppose the most valuable thing I have is an understanding and supportive wife.