Serious:
Without humor or expression of happiness; grave in manner or disposition; earnest; thoughtful; solemn; Important; weighty; not trifling; leaving no room for play; needing great attention; critical.
Gee, where do I sign up? Sounds like a great recruitment poster for ascetics or perhaps flagellants - can we get a logo with our horsehair underwear or do we wear the sackcloth and ashes only? I nominate Cotton Mather as our first interim president.
THERE WILL BE NO JOCULARITY!
Anecdotal, and on a personal level only, but several folks at my sporting clays club are NRA benefactor members while I've had several "serious" handgun range ninjas explain to me at length why they don't feel the need the contribute to any pro-gun organizations. Not being satisfied by their own lack of will, they will cheerfully go online to explain to others why they shouldn't contribute either.
Life is too short for you to spend it fretting about whether I'll be there when your EBR is under attack - do your part and quit worrying about trying to herd cats. Just make sure you're there when they start talking about "arsenal licenses".
It's probably just me but I have something of a negative view of "serious" in the context of firearms fora. A number of unpleasant images pop up, quite unbidden, when the word is mentioned:
I see posts from people loudly decrying being swept with a disassembled gun.
I read reports of folks emailing sympathetic radio hosts chastising them for being photographed with bad trigger discipline - thus convincing the individual we're a bunch of bedwetters.
We're so serious we'll actually go out of our way to post Youtube videos of people making gun owners look like lunatics thus scuttling any chance that the thing will just go away - this is no doubt a subset of the logic that compels people to post "troll!" in a thread thus propelling it to the top of the page.
We go out of our way to alienate writers that cast us in a favorable light because they weren't absolutist enough to suit us (Abigail Kohn - not that I expect anyone to remember). Excoriated on every forum she visited - I was sooo proud of our serious brethren. /sarcasm.
They scold our own membership when photos are taken of the muzzle end of a firearm.
I read pompous declarations stating that there is no such thing as an accidental discharge - only negligent. Repeatedly. Over and over again. Did I mention it's repetitious?
We engage in endless debate over magazines, clips, long Colts, MIM, EDM, Ford, Chevy and can cite minutiae. When we're being serious we have an uncanny ability to spot fly droppings in ground pepper. And care. We'll chase away newcomers that we desperately need if they use the wrong terminology.
We are uncritical when something serious comports well with our prejudices and will cheerfully post links to dead polls, breathless whining over HR45 and 14 year old Australian statistics offered up as "fresh last week". We are suckers for chain email.
...granted, most of low opinions I hold on "serious" are likely a personal problem.
Still, I believe it was Jeff Cooper that was growing weary of "The California Scowl" whereby someone would complete his string of fire then glare menacingly at the adjacent dividers before holstering his weapon. Presumably the "California Scowl" distinguishes serious practice from mere practice.
Lighten up.