The Scot was confirmed as new coach at the Liga side earlier this week, after Jagoba Arrasate's sacking at Anoeta, ending his managerial exile that dated back to April when his ill-fated tenure at Manchester United was ended less than 12 months into a six-year deal.
Moyes once again stated that he received offers to return to the Premier League and elsewhere in Europe, but revealed that the chance to manage in Spain's top flight with Sociedad was the one that appealed most to him.
"I had several offers to manage back in the Premier League and I've spoken to clubs in several countries," he said.
"But the only one that tugged at my heart was Sociedad. It's given me the chance to manage in La Liga.
"It's the best league in the world, I would say it's taken over the Premier League, because of the players here and the fact the teams are regularly getting in the finals of the Champions League [or] Europa League."
Moyes endured a frustrating spell at Old Trafford, losing 11 of the 34 Premier League games he took charge of.
However, the 51-year-old insists he has not lost any self belief from his time at United, while stating that the enthusiasm of Sociedad president Jokin Aperribay also convinced him to return to coaching.
"I never had any doubt [about my ability]," he added. "What convinced me was the president. He was fantastically passionate about his club.
"He told me how special it was and what it means to him and his love of the club pulled me.
"It's always been an ambition of mine to coach abroad. I think to be fulfilled you have to enhance yourself and try different cultures. I'm well rested, I've had six months off and I'm raring to go."
