When do memes die off?

[put your faith in me]

After a few months? When did Scumbag Steve meme die out?

[jasonh1221]

There's no average lifespan - each one lasts a different time in popularity, based on relevance to pop culture, generational use, and other factors. Scumbag Steve, for example, is still used daily in places like reddit

[Minister of Truth]

such are fads

[Ocelot]

Memes usually die out after a couple days of it being popular, but if it's really good it can last years.