A city IT worker is suing a train operator for nearly £2m in damages after losing both his legs when he fell between a train and a platform looking for his lost season ticket.
Matthew Robinson, 34, was on his way home from work in London when he fell into the "significant" gap at Bishop's Stortford Station in January 2013.
The commuter had left his £3,000 season ticket on the Stansted Express and was walking alongside, looking through a window, when he lost his footing and fell.
The train ran over his legs, causing the loss of one above the knee and another below, leaving him needing a wheelchair.
Suing operator Abellio Greater Anglia Ltd for £1.9m damages, he claims not enough was done to ensure safety at a station with a large "platform train interface".
At the High Court, he told Judge Martin McKenna: "I knew there was a gap, but I wasn't aware at the time how significant it was."
His barrister, Brian Cummins, told the court the Liverpool Street to Bishop's Stortford platform is long and curved, with an "excessive" gap in places.
Mr Robinson, who lives in the Hertfordshire town, said he had been in a "distressed" state when he realised he had left his season ticket on the train.
He had lost one before and did not want to be out of pocket, so returned to the train to retrieve it.
However, he went for the wrong carriage and the train was already moving before he could get onto the car where he had left his card.
Footage played in court showed Mr Robinson walking alongside the train in the direction of travel and then disappearing as he fell into the gap.
Giving evidence, he told the judge that, although he had been commuting to and from the station for nine years, he had rarely heard "mind the gap" warnings.
And although he said he knew there was a gap, he added: "I was unaware it was as large as this".
Abellio denies liability, and suggest Mr Robinson was so stressed at the thought of losing the £3,000 ticket that he was "completely distracted".
The hearing continues.