When I got my call in the late fifties, I had my fingers in lots of 
equipment.  I wanted to know the feel of paper capacitors, disk 
ceramic and ceramic capacitors, electrolytic caps. and 
resistors.  Knowing what they felt like helped me understand how they 
worked.  And feeling them in circuits also helped me with the 
electronic concepts.  New amateurs with PC boards and ICs sadly are 
missing all of that.
And I also discovered 500 volts from an 807 plate cap!!  The smell of 
RF ed fingers is unforgettable!!  And R F burns took a while to heal!
Pat, K9JAU