How I got transistors WRONG

So I've built a few things using transistors so far, and I thought I understood them.

I thought NPN meant that its input was "N polarity, so you put "P"ositive voltage to its middle pin, to get power to leave through the other N. Because opposite charges attract::conduct, or something. And for these transisors it was pretty much true.

Similarly, I thought PNP were just the opposite: you put a ground to the middle prong to let its power go through... it worked in breadboard tests with LED lights and such.. but that basic "understanding" was fundamentally wrong! And it turns out I had a LOT of fried PNP transistors sitting around, because guess how my transistor tester "tested" them?

But thats a good thing! As frankly, I was stumped on how to work "connect 0v to base" into any circuit design, and PNP transistors sat in my parts bid collecting dust.

Then I did some book learning... turns out what I was doing by putting a ground to the base of a PNP was simply using that base as the circuit instead of the emitter... or some other esoteric electronics misuse of a transistor I cant claim to understand...

Then I followed a step by step walkthrough of transistors.. from NPN, PNP, and SCR styles, in step by step breadboard demonstrations I could assemble and do as I read it.

This is when I finally learned than a PNP transistor is like a Normally Closed switch.. the opposite of how an NPN is a Normally Open. Each is controlled by Voltage to the base, but the PNP kills the power, the NPN turns on the power, when the base is activated.

The reason I never figured it out on my own is because an NPN was simple; just leave the base empty, put a 1k resistor between power and its base, and "click!" it turned on. A PNP was not so simple. It just didnt work. It was supposed to already conduct with nothing on its base, but it was just dead. Putting power to its base didnt do anything if it didnt do anything to begin with! The secret, I learned, could have been summed up in 3 words... that had anyone mentioned them to me, would have made me instantly figure it all out:  "Pull Down Resistor"!!

I guess the base of a PNP with power sitting in it sort of hovers around its own shutoff levels if left to its own devices. Putting power to it then, only reinforces its OFF state. A pull down resistor- it doesnt matter if it was 10M ohm- would force that base to be ZERO, and the PNP would function as normal. Adding +V to the base now would shift that "floating but pulled toward zero" value to a real, +V power, and turn it off, or regulate it, or whatever. Now I get it.

And now that opens up a whole new world of solid state switching to me, as now I can puzzle out a solid state DPDT relay, or a self latching power-on hold circuit, or a Coil Gun trigger mechanism that will turn on/OFF at nearly the speed of light... stuff I was just scratching my head about last week!