The star's mum, Elsie, passed away in 1986, but he only recently found the time to go through all of the boxes which had been taken from her home in Liverpool, England.
Starr reveals it was an emotional experience for him, as he found she had kept all kinds of keepsakes from his childhood right through to his time in The Beatles.
He tells Britain's Daily Mirror, "It was like an Aladdin's cave - a treasure trove of memories. Mum was a bit of a hoarder and she collected all this amazing stuff from my life. There were baby pictures, ones of me with Nurse Edge when I was in hospital with Tb (tuberculosis) aged 14, the receipt for my first drum kit, my report card from technical college where I was studying to be an apprentice engineer, stuff like that.
"Later, even when I was in The Beatles, she must have emptied my bag or my pockets when I came home and put random things away. I'd never have saved that stuff. There were notes and memos from Brian (the band's manager Brian Epstein) - 'Make sure you look smart tonight, lads, it's a big show'.
"That woman loved every second of my life and remembered every second of it."
Starr has published some of the photographs he found in his mother's belongings in his new interactive multimedia ebook, titled Photograph.