Even at an early age, I remember my dad bringing home old equipment from his job as a Biomedical Engineer. Sometimes it was a microscope that had been decommissioned or an oscilloscope with a bad channel that was beyond repair. Or maybe even just a random circuit board that was rife with components for salvaging with a soldering iron and a desoldering pump.

Before parts suppliers like Adafruit. Before buying parts on ebay and aliexpresss direct from china. Back when digi-key was just a (paper) catalog business.

Even then, parts were everywhere. 

Now, $20 and a paypal account will get you more arduinos, transistors, LEDs and jumper wires than you know what to do with. Not to mention bearings and 3d printer nozzles and dc-motors and connectors and...