The former Owls left-back says he could have prolonged his career by another five years.
Gray, who played Premier League football for Sunderland and Blackburn Rovers, arrived at Hillsborough in 2009 as 34-year-old.
But despite featuring regularly for the Owls over an 18-month period, Gray opted to hang up his boots upon Wednesday's relegation to League One.
Gray provided the assist for Tommy Spurr's goal at Bramall Lane as Wednesday recorded their first double over Sheffield United in 95 years
Speaking to Talksport on Thursday morning (c. 10:20), Gray said that, where some youngsters were concerned, he'd never seen anything like it in his life.
"I could have played until I was 40," the Mackem told the Colin Murray show. "But I got to Sheffield Wednesday and I’d never seen anything like it in my life. It made me quit."
Gray, who described the attitude of some as 'one game and I’ve made it', added of one young player in particular: "He was sat in the dressing room with his headphones on, dancing around to his own music - and then played a football match."
The former Celtic, Leeds United and Wolverhampton Wanderers man refused to single out individuals, but stressed their behaviour was beyond the control of managers at the time Brian Laws and Alan Irvine.
Gray was signed by Laws (L) but left under Irvine
After retiring, Gray, who scored twice in 44 Wednesday appearances, moved into the punditry circuit and regularly appears as a guest on both Talksport and the Football League's highlights package on Channel 5.