It might be teddy boys, old episodes of the children's programme Andy Pandy or the original Star Wars movies that make you feel nostalgic.
Memories that tug on the heart-strings are now the subject of research into how UK charities can use nostalgia to get donors to open their chequebooks.
The project, led by John Ford, professor of marketing and international business at Old Dominion University in Virginia, US, will develop a scale on which charities can measure how the tendency to give is affected by evoking certain emotions and memories.
It builds on similar research he has undertaken in the US, and charities will be able to use the information to help them develop fundraising campaigns.
Ford's American study asked more than 500 US donors who had given to charity in the previous 12 months about what made them feel happy, sad, lonely or angry. They were encouraged to remember significant events in their lives and write down how these made them feel. They were also asked if they were more likely to donate if the events were linked with a cause.
Ford told Third Sector the UK study would talk to a broader range of donors by using online surveys as well as charities' donor lists.
"We will look at how the level of nostalgia felt by the person affects how much benefit they see from connecting themselves to a charity, which in turn leads to commitment and intent to donate," he said.
"We think nostalgia might get through to people when other things don't."
Using nostalgic images had produced good results for many US organisations, including the Public Broadcasting Service, a not-for-profit broadcaster, which used a familiar Sesame Street character to encourage viewers to tune in to the channel, he said.
James Briggs, co-founder of UK marketing firm Open Fundraising, said nostalgia definitely had a place in UK fundraising, but what worked for one person might not work for another. Tighter targeting or more creative variants could be needed, he said.
Richard Hill, planning director at UK marketing firm Touch DDB, said charities should be careful not to portray themselves as hankering after the past and having no modern solutions.