The Sweden striker arrived from Newcastle United on deadline day in September 2025 for a British record fee of £125 million.
"Liverpool is a massive club, and everything about the club made it pretty clear," Isak told BBC Sport. "And the club's ambition and the club's will to get me in as well. It was a big part of it."
Isak missed pre-season last summer and trained at his former club Real Sociedad amid uncertainty over his Newcastle United future, later saying promises made to him there had been "broken." He then struggled for goals in his first season at Liverpool before a leg break ruled him out from December to April.
This season, by contrast, he has already matched last term's tally of three Premier League goals after just four games. Asked whether he ever regretted the move during that difficult period, Isak was unequivocal.
"No, never. I would never think like that," he said.
"[The leg break] was tough. Anyone who had a long injury would know," Isak added. "But on the other hand, when you're in a good place and when you feel good, you don't really tend to look back because it doesn't really benefit you. So I'm just looking forward and feel really optimistic and excited about the season, and what it can bring to us."
Isak made his World Cup debut for Sweden over the summer, having managed only 1,032 minutes across 22 Liverpool appearances the previous season, and scored once with three assists under Graham Potter before Sweden were eliminated by France in the last 32.
"Playing for your country in a World Cup is a dream of most people," he said. "With the injuries last season, the World Cup was perfect. I had that period where I could play and gain rhythm and form. And, on top of that, it was a massive experience, so that was perfect to do and come back here for pre-season and to start the season."
New Liverpool head coach Andoni Iraola, who replaced Arne Slot in the summer, has asked Isak to defend from the front, framing it as attacking rather than defensive.
"He asks me to be part of the defending but to defend in positions where, when we win the ball, we can counter quickly and get the ball forward to the offensive line," Isak said. "He said 'score goals', but he wants me to defend. The way we defend — we defend to score goals so defending, in the end, is an attacking weapon."
Isak said Iraola's front-foot approach, which has seen Liverpool make more sprints than any other Premier League side this season, suited his own game.
"He came with his football — the way he wants to play and the high intensity which I think will benefit me, the club and the way the club wants to play football," he said. "It's not just about getting the ball to me, it's about getting the ball forward and to all of the offensive players quickly. I think that will benefit the team. I think if we can do that then we should score more goals."