Here are 5 easy ways to tell if you might take smash on kaillera a little too serious. I'm guilty of some of these so i'm not being a hypocrite.
1. you play ppl multiple times in hopes of beating them once so you can upload it, sometimes staying up all night to do so, examples: MATTS!, smasherx74, xelpherpolis, me
2. you get to the match in less than 5 seconds
3. you always turn off music
4. your in a clan
5. any time you lose its either because you sandbagged/didn't try or your opponent camped, gimped, or somehow cheated
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1. That's maybe a little competitive, but come on, I did that against people I knew even when I was a no-kaillera scrub. People do that in a lot of different games, and not just ones that they're serious about; for example, I know a bunch of people who'll demand another one-on-one basketball game if they lose the first one. As for the "so you can upload it" part, you're being an idiot. That's not a too-serious thing- I should know, I think smash is SERIOUS BUSINESS more than almost anyone else I've spoken to- that's just a ******* thing. Show some maturity, honesty, integrity, or really any virtue along with your overcompetitiveness, and that won't happen
2. meh. Come on now, man, that's tantamount to saying "you've played the game a bunch of times before". Would you rather we did an items-on kirby dittos match on sector Z? or would you like us to slow down because we've done it a million times so we go too fast?
3. matter of opinion. I used to turn off some stage musics in my consolenoob days. It can get boring or distracting.
4. This is the only legit one. Not always; a bunch of people are "just in clans for fun" (blech) or else they clan with a moderate amount of coolness about the whole thing and play to win, but don't get worked up when they lose, and keep at least a little perspective on the whole "It's a video game" thing. But being really into your clan to the point of annoyingness gets old REAL fast.
5. That's just Noobishness. If they gimped, shut up and play better/play a better character/play someone who'll conform to your set of "smash rules". If they camp, shut up and play better, find a different person to play, or go cry to yourself. If you must tell them about it- and in some cases, this is the best recourse- Instead of ragequitting, going into the lobby, and saying "wow wut a ****ing nub pikas chep u camp like a ***** just admit it u lost" try something like "hey man, would you mind playing a lower tier character? I really wanna work on my weegee and your pika's just gonna **** me" or "would you mind attacking more? I feel like you're camping a lot and it's funner if you don't do that" I find that the people who complain about camping are usually the ones who play kirby against your samus and then whine about cheapness when they lose. You can always politely take your leave of someone who really pisses you off.
Overall, your list isn't so much a seriousness thing as a total prick thing. Granted, being a prick about smash means you're taking it too seriously, but taking it very seriously isn't a bad thing, even when it results in horrible occurences like lack of music and quick itemswitching.