At 6ft tall, the package was tubular in shape and large enough to contain a shark - crushing my mother's hopes for a diamond skull. Without a van to drive us back to my studio the only clear option was a ride on the 73 bus, with the Damien Hirst reclining on the seat beside me. The perfect ending to my #averagejoe adventure.
A year ago today I was en route to Paris after a gruelling seven days spent travelling between New York, Los Angeles, Rome, Geneva and Athens. Over the previous week, I had sold 500 shares in a bid to raise the £10,000 I would need to compete in Damien Hirst's exclusive globe-spanning Spot Challenge.
Now the journey that has dominated my life since 2011 comes to a close: not with a flight from Hong Kong to London to receive the final stamp in the challenge, but - twelve months later - with a much shorter journey home from the Gagosian Gallery in King's Cross where I eventually collected our prize.
As I began to unwrap the package it dawned on me just how differently things could have worked out: the shares may not have sold in time; the Greek austerity riots could have left us stranded in Athens; while my stamp card (the only proof of our progress in the challenge) might never have been handed in at Flumicino airport. At any given moment, the 293 shareholders who invested in my idea could have been left empty handed, crushing both their dreams and mine of an #averagejoe victory.
Fortunately, on this occasion the odds were very much stacked in our favour. You can imagine how relieved I felt as the colourful dots belonging to an artwork titled 'Hypothalamus Acetone Powder' slowly began to materialise. At last I could celebrate with the group of friends, family and available shareholders that had gathered inside my studio.
Scribbled along the base of the 59x53 inch print read the message 'For Josef Love Damien Hirst' along with three playful sketches of a shark, butterfly and diamond skull - to which my mother pointed at with glee. A unique work of art worth a significant amount of money, now co-owned by a group of people who could otherwise not afford such a luxury. 'So which part of it belongs to you?' asked one of the onlookers, as I stood glaring down at the floor. It suddenly dawned on me that I had come this far without owning a share of the prize myself.
So why had I put in all the effort? I'd built a website with no money. Sold 500 shares. Created a promo video in the hope that it would go viral. Recruited a cinematographer. Raised £10,000 in under a week. And then embarked on a journey spanning 30,000 miles around the world - all this, in just 19 days. But why?
In 'The Story of Dorian Gray', Oscar Wilde describes the basis of optimism "as sheer terror", and sat on my bedroom floor all those months ago I remember feeling energised with the fear of knowing that my idea was too ambitious to achieve - yet too exciting an opportunity to ignore.
I was going to create my own work of art - titled '#averagejoe' - from an experience shared amongst the many thousands who had watched my youtube video, purchased a share online and accommodated me around the world. From staying with the Downey family in New York to being driven to the airport at 4am by someone who'd heard about the project on twitter - the human experience I had gained from this adventure was worth more to me than any material reward that Damien Hirst could have offered in spots.
Instead of being the common property of humankind, I have grown up to view art as the property of somebody who could actually afford it (i.e not #averagejoe). A commodity that defines itself not through meaning, but how much it is worth - a notion Francis Bacon disagreed with. He believed that artists held a unique responsibility to share their vision with the world in the same capacity as a civil servant, but could you really imagine paying £15 Million for a health checkup?
Over the next few months I will be dividing up the shareholders' stakes and fulfilling my promise of creating 293 artworks in exchange for their twenty quid. All together - who knows? - the whole thing might just be worth more than a Hirst...
Follow Josef Valentino on Twitter: www.twitter.com/JosefValentino