From shopping lists to love poems: Our discarded jottings say much about our lives

A Freemason staggers drunkenly though a park; a child throws a toy hippo on to a roof; a devotee of the Mountain of Fire and Miracles Ministry composes a forlorn prayer to God; someone, somewhere, forgets to buy potatoes.

The one thing that ties these events together is the paper trail they left in their wake.

For the past five years, Central Saint Martins graduate Daisy Bentley has been obsessively scouring the streets for lost or discarded notes, panning the gutter for tiny fragments of heartbreak, hope and, yes, forgotten shopping lists, too.

"I find about a note a day on average," says the 23-year-old artist when I meet her at east London gallery Stour Space. "I can't stop. I refer to my work as sort of collecting poetic moments. It's about finding little bits of humanity." Her collection goes on show today at the gallery.

The 150 notes on display, which have been painstakingly selected from a collection of more than 1,000, form a kind of patchwork quilt that envelops all of human experience, from cradle to grave. An expectant mother wishes for a boy; a child cries off school; a deaf and disabled grandfather reaches out. The spores of gentrification blow in the wind: a shopping list found in London's aggressively regenerated Hackney bears the reminder "truffle oil and craft beer".

Scraps of hidden London flutter up through the cracks in the pavement, too. One particularly profitable note-finding foray into a local park yielded a "Masonic briefcase", presumably dropped by some ale-fuddled inductee, complete with "hat, sash, certificates" and secret rites of passage.

Thanks to social media and our ever-present smartphones, most of us are bombarded with a hundred random insights into the lives of strangers and friends before we've even rolled out of bed. What makes the Found Notes exhibition special, perhaps, is that the insights it affords are stolen. At times it seems almost unethical. "My Lord," reads one tragically short note. "What have I done to deserve this..."

"A lot of people don't understand why I value the notes so much," says Bentley. "I refer to them as my babies. It's the only thing I can really compare it to. Someone asked if they could buy one a few years ago – one of the original notes. I told them I'd get back to them with a quote. I told them, 'It'll be £30,000, please.' They politely declined... I don't know what I'd even do if someone offered it to me – I might not be able to do it!"

Collecting perhaps runs in the family. Bentley's mother, Lisa, works as an archivist at a Norwich museum. "Her collecting is contained in her job," says Bentley, "whereas mine seeps into other areas of my life."

Some of it is a little weirder than just cutesy notes: a chromatically ordered hair collection takes up much of her tiny flat, and a menstrual blood bank is in the pipeline. "It's something I want to do just for fun," she explains. "I'm not sure what it's going to be yet."

What motivates Bentley to collect? The human psyche is a contrary thing. As Jung understood more clearly than anyone, one psychic event can often end up producing its extreme opposite. Perhaps, I suggest, this mania for finding and collecting stems from some great foundational loss?

"I lost my father when I was 11. Maybe that's got something to do with it," the artist muses. "Maybe now I'm collecting all these little bits of other people's emotions because I lost something early on... He was only around until I was 11, so it's early memories, very absurd sense of humour... I think he'd like these kinds of projects."

Found Notes may be considered by some to be trite, but in its own small way it manages a Herculean feat. Gleaning a little humanity from the city's harsh and unforgiving streets is no easy task. Perhaps one of the notes can sum things up best: "You Are Not Alone".

Found notes runs until 4 May stourspace.co.uk/event/found-notes-daisy-bentley