Recalled by Southampton earlier this month, he remained at Wednesday for seven days due to a clause in his loan contract.
During that period, he played in matches against Leeds United and Bristol City before finalizing his return to the Owls for the rest of the term.
Charles told the Star: "It's been a little bit chaotic.
"Obviously, the deadline for my recall was the 15th and I got recalled on the 15th. It was very last minute, and I didn't really know what I was doing for that seven-day period.
"I was so relieved and happy it got sorted. I came here for a season-long loan, that was the plan.
"I didn't really want to cut it short because it's a great group of lads and a good coaching staff.
"Everyone around the club is really pushing for something. I’m excited to finish the season here.
"I like to think I had a good influence on things because I was quite firm in staying here, and my agent knew that and Southampton knew that.
"It's a weird one, any interest is good interest, but I was always focused on staying here. They (Saints) have seen that I've progressed well this season.
"Now they're more than happy to see me finish the season here. I think it’s good for both parties.
“They’re happy to see me stay at Wednesday because it's a big club and good coaching staff and good team, players like Barry Bannan and Nate (Chalobah) to learn next to.”