An apology in advance: Sorry, I may end up ranting.
We all have our pet peeves – little things which really really really annoy us and we don't know why. Our annoyance is not proportionate to the action. If someone tries to run you over, then getting mad is reasonable. If someone puts the milk carton back in the fridge with only three drops of milk left in it and you throw a fit – you're overreacting. Your annoyance is understandable, of course, but not entirely rational. Full disclosure: I have been known to put the nearly empty milk carton back in the fridge and so I humbly apologize for provoking ire.
Then there are the pet peeves which pertain to spelling and grammar. Some people clench their teeth over the confusion of your/you're, then/than, and the like. Other people get fidgety when infinitives are split or metaphors are mixed. While I can't say I've never twitched over the aforementioned, one thing which makes me feel like some cruel being is scratching his or her fingernails up and down a blackboard with malicious intent is the phrase "instant classic." If you've never come across it (too late now, huh?), it's supposed to mean something was really unbelievably fantastically mindblowingly fabulous as to make you and everyone else take note of the thing's existence and never forget it. Urban Dictionary says it was coined in a Washington high school.
I don't care.
I can deal with "tweet" no longer referring to the sound a bird makes. I can cope with Facebook turning "friend" into a verb. By now I'm used to "text" being used as a verb. But I will never get used to that stupid oxymoronic "instant classic."
"Instant" implies immediacy, "classic" implies a quality recognized retroactively, as in a while later, usually a long (long) while later. There isn't a specific amount of time to determine the object/subject's status as a classic, but it's damn well longer than an instant.
So by all means-
Say it was stunning.
Say it took your breath away.
Say it was an instant sensation.
Say it took the world by storm.
Say it created an immediate craze.
Say this thing or this moment will probably be remembered a long time from now.
But please don't say it's an instant classic.
That makes no sense.
It's like saying someone/something is suddenly traditional. Or casually uptight. Or calmly upset. Or spectacularly ordinary. Or incredibly realistic. Full disclosure: I've used "incredibly realistic" on more than one occasion. Nobody's perfect. Which reminds me – you can't be perfectly flawed or exactly imprecise either. I know this doesn't have much to do with writing other than belonging to the mistakes-to-avoid category, so I welcome everyone to share their writing pet peeves. I feel so much better now that I got that out of my system.