Get in the car... turn on the stereo... how many watts are you using?
Sit on couch... turn on TV... set the volume.... How many watts are you using?
Answer the phone... set the volume... Watts?
Shove some bread in the toaster... how many watts are you using?
Slice of Pizza in the Microwave... How many watts are we using?
The correct answer is "I don't know"... these consumer products are intuitive enough to be used without knowing ohms law, yet... ohms law was used to figure out how to make the product, but after that, the consumer uses the senses required t know what is right for them.
AS FAR AS I'M CONCERNED... a well designed consumer product doesn't require the consumer to know ANYTHING involved in the tech of how the magic is made.
Your Car stereo is set by the volume that is comfortable to listen, Same thing with the phone and the TV. Bread miraculously becomes toast, if it's too light ya turn it up, too dark... down. The pizza is too hot? Lower the power, or put it in for less time. And Vice Versa if it's too cold.
With these regulated devices you NEVER need to know the resistance, the voltage OR the wattage. Amp limits? NEVER.
Start low, work your way up until it tastes good... watts or Volts... who cares. They could be letters or symbols... doesn't matter. It's an integer so you can remember where you were when it tasted good.
The rest... well, kids, it's all just overthinking it, to be honest. Yes you CAN do all kinds of math, it changes nothing... it gives you a data point that is completely pointless.
And when the battery is dead, I charge it.
At the end of the day, what matters to me, is that the vapor comes out when I push the button. If it's too hot, I turn it down... too cool, I turn it up. And that's all anybody else does too... they just put in a whole bunch of mystical mumbo jumbo so they can pretend they know the Rosicrucian secrets.
UP or DOWN... everything else is a traveling medicine show acting as a speed bump on the path to shoving nicotine all up in my face.
A toaster that can't be set to at least 60 watts doesn't meet my breakfast needs.