Ayling was a key member of the Leeds side that won the Championship in 2020, ending a 16-year period outside the top flight for the Yorkshire giants.
He was there for their three-year stay in the Premier League, but was unable to prevent their relegation in 2023.
And his departure came after losing his place in the team under Leeds’ current boss Daniel Farke.
“I found it tough to leave at the time that I did,” Ayling told the My Mate’s A Footballer podcast.
“I still felt like I could help the team and get them to where they wanted to go.
“But it all came down to myself wanting to play football. It was either stay there for six months, sit on the bench or even not make the squad, or get out and play some football.
“I’ve been given a home at Boro and I’m really enjoying it.”