Oleksandr Zinchenko revealed he was laughed at by his Arsenal team-mates when he said the club could challenge for the Premier League title.
The Gunners furthered their grip on the top-flight summit with a dramatic 3-2 win over Manchester United on Sunday thanks to Eddie Nketiah's late winner.
The result moves Mikel Arteta's men five points clear of Zinchenko's former club and champions Manchester City, with Arsenal possessing a game in hand as well.
Reflecting on another crucial three-point haul, the Ukraine international talked of encouraging his team-mates to enjoy the moment, after initially doubting their credentials.
"I said to the lads before the game, 'When everyone is going to retire, we're going regret that we didn’t enjoy enough'," he told Premier League TV.
"Everyone realises we have a lot of games ahead of us and we just go step by step. The mentality and spirit is right. That's the key.
"Of course, there is a lot of space to improve but we are [heading] the right way When I arrived, the quality I saw, I realised that we have everything to achieve the big things.
"I started to speak in the dressing room [that] we needed to think about the title. Some of them were laughing, but no-one is laughing now."
Zinchenko will get the chance to face off with old side City once again this coming week when the pair meet in the fourth round of the FA Cup, before Arsenal kick off February against under-fire Everton.