Some people's stupidity....
If this is tl;dr then just skip to the end.
Last night, some friends and I were changing spark plugs on someone's truck. Well, then someone else shows up (a somehow ASE Certified mechanic) and starts acting like he knows everything about everything ever, but basically proving just the opposite to everyone.
"This is not the right plug for this truck. See how this one (original platinum) has a pointed tip but this one (new copper) doesn't? That means that (louder, cockier) this is NOT the right plug for this truck!"
"The numbers don't even match up!" (comparing original NGK to new AC Delco)
"I have AC Delco triple platinum iridiums in my truck!"
No one was really saying much about him or arguing with him... then I decided to. I told him you can't get a plug that's both platinum and iridium, it's either platinum or iridium; I've heard of triple platinums, and iridiums, but never triple platinum iridiums because they don't exist. He started throwing around his ASE Certification (which meant nothing to me before, and even less now) and I told him "I work at a f'in parts store, I would know this!" Then all remnants of intelligence disappear and he just threatens to slap me. I didn't even get a chance to tell him why the tips look different (plats vs copper, duh) and why the numbers don't match (NGK and AC don't have the same numbers because they're different companies), but oh well, I had my fun making him look like even more an idiot than before in front of something like 10-12 people.
Blah blah blah, long story short, the truck ran better with the new coppers, the idiot left saying "F you guys," to which almost all of us replied with a "F you too," and ASE Certification doesn't cure stupidity.
Needs more stall.