I think, or at least imagine, it has always been the case that a shorter passage of time need pass before nostalgic tendencies develop in younger people.
To a teenage girl, a few years will clearly appear to be a far longer time span than to a woman twice her age.
However, the digital age appears to have ushered in a new era of early-onset nostalgia.
In much of the social media research I've done, younger teens are increasingly reflective when discussing brands that they used to eat, drink or play with only a couple of years ago.
It's easy to envisage it has always been this way but I think social media, and the particular way younger people use these sites, is playing a big part in advancing this.
For most adults, Twitter is primarily a broadcasting tool and the intention is generally to reach as many people as possible.
As the widespread infatuation with tools like Klout highlights, people (and 'professionals' in particular) are increasingly obsessed with showcasing the impression of digital influence.
For this type of user, the number of people following you is the most obvious illustration of your social media success.
In contrast, teenagers are far more likely to use Twitter as a tool through which to engage in genuine conversations; hence the increased likelihood they will 'lock' their profile as private, often referencing a stranger following them as 'creepy'.
For many teenagers, the number of times they've tweeted is regarded as more of a badge of honour than the number of followers they've acquired.
Younger Twitter users frequently reference milestone tweets, and indicating how long and often they've used the site appears to be more important than how many people are actually paying attention to them ("4000 tweets is a big accomplishment for me!").
It's hardly surprising that tweeting thousands of times a year, and being reminded of that tally on a daily basis, creates a greater sense of more life having been lived than is actually the case.
Perhaps in a period of uncertainty, encroaching student debt and widespread youth unemployment, there is an ever stronger desire to cling to the familiar and those brands which remind young people of their early teenage years take on a heightened and more immediate importance.
There's a clear opportunity for 'fun' brands, like children's cereals and soft drinks, which are encountered on a daily basis to leverage, or even create, excitement without the need for a specific social media campaign.
J2O's Glitter Berry is an example of a launch that caused near breathless excitement amongst many teenage girls, keen to Instagram photos of the glittery drink and share them with friends on Twitter and Facebook.
Very simple and classic marketing tricks, like adding a toy to a cereal box, can often spark more online enthusiasm than a campaign aimed at generating social media 'buzz'.
Nostalgic brands typically lack relevance but this newer form of 'digistalgia' appears to provide an opportunity for a much wider range of FMCG brands, in particular, to tap into.
(image courtesy of Spree2010)