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.
There’s also a lot of snake oil in the hobbyist/personal hi-fi audio world. I’m a professional audio tech for live events. A lot of people don’t understand how audio works, and why audio gear is built a specific way. So they’re susceptible to bad faith sales tactics, which are oftentimes inventing problems that never existed before the product was being marketed. Or claiming to use manufacturing materials/processes that won’t make a difference on a physics level, but will make a difference in cost to the end user.
Hi-fi audio is a world of diminishing returns. A $1000 system will sound great compared to a $500 system. A $5000 system will sound a little better than a $1000 system. But a $10,000 system will only sound marginally better than the $5000 system, and many people won’t even be able to tell the difference between the two. Or to rephrase, they’ll be able to tell a difference between the two, but won’t be able to tell which one is the “better” system. They’ll simply hear the difference in speaker frequency responses.
Also, that classic rock song you’re critiquing on your $30,000 living room sound system was performed and mixed by people who couldn’t hear fucking anything. Their hearing was shot years before the song was recorded, by decades of crowd noise and stage monitors.