For me it’s driving while under the influence. If you couldn’t tell, I like me some ganja. However I have long since held the belief that it is utterly insane to drive while under the influence of most substances, with maybe nicotine and caffeine being the exception. All too often I see other stoners smoking and driving, which I simply can’t fathom. I’ve only operated a vehicle once under the influence and it was just to move a U-Haul around the block to a different parking spot, which was such a scary experience while high that I refuse to even consider getting behind the wheel again while high.
NP. One more thing I did was read a book called Pass Your Ham Radio Technician Class - The Easy Way. Hamstudy is really good for practice, and memorization, but it doesn’t really explain the principles behind the answers. That book does a great job of explaining things like bands, frequencies, tones, etc… You’ll have a much stronger understanding of how things actually work, instead of just having answers to questions.