As a child Thomas Newman collected baseball cards which he kept in a shoebox in his room.
But when his mum threw his precious collection away he was so devastated by the loss that he decided to replace them 40 years ago.
The neurologist would spend every summer travelling across the US to attend special conventions where he would boost his collection that he affectionately called his 'paper babies'.
Dr Newman was so passionate about his cards that he would refuse to sell any of them, even if he was offered up to 10 times what he had paid just days later.
The only exception is if he managed to find the same card but in a better condition.
When the 73-year-old sadly died from coronavirus in January his family were tasked with going through his belongings and have now put up his collection of baseball cards and sports memorabilia for sale.
It has been called 'one of the finest collections of its kind' and is expected to fetch a whopping £14million at auction.
His widow Nancy said: "No one enjoyed collecting more than Tom.
"He jokingly called his cards his 'paper babies,' and spent almost every day attending to his collection in one way or another. It gave him such pleasure.
"The only reason he would ever sell a card was if he had acquired the same card in a higher grade."
Dr Newman's son, Stewart, said his dad started collecting in the 1980s to replace the cards that his mum threw away and he would happily travel across the country with his dad to buy more.
Recalling the pair's annual summer trip to the annual National Sports Collectors Convention, he said: "The only downside is that I never got a lunch break because he was on the go from the minute we entered the convention hall."
Auctioneers say one card - a rare Babe Ruth cards from 1933 - is worth an eye-watering £3.6m.
JP Cohen, President of Memory Lane Auctions, which is managing the sale, said other valuable cards in Dr Newman's collection include a near-perfect Mickey Mantle rookie card from 1952 which is expected to sell for more than £700,000.
Dr Newman bought it in 1986 after it was found that year in an original case of 1952 Topps baseball cards in Massachusetts.
The medic amassed such a large collection that when Mr Cohen went to Florida to pick it up, the collection filled an 18-foot long truck.
Some of the late doctor's collection were stored in a room at his workplace which was filled with boxes of unopened cards from the 1980s.
Mr Cohen said: "This collection is the finest known of its kind. Prices for rare, historic items have exploded in the collectibles market.
"If Dr Newman paid $500 (£350) for a card he really wanted and a week later someone offered him $5,000 (£3,500) he’d turn it down.
"He just had an unquenchable thirst for sports collectibles. He loved it all."
The collection was authenticated and graded by Professional Sports Authenticator which is the world's largest sports collectibles certification company.
The collection will go up for sale at an online public auction from June 21 to July 10.
