Hughes, who takes his Stoke side to Craven Cottage this weekend, resigned as Fulham boss in the summer of 2011 having led them to an eighth-placed finish and Europa League qualification through the Fair Play League.
At the time, he said: "As a young, ambitious manager I wish to move on to further my experiences", while then owner Mohamed Al-Fayed branded him a "strange man" and a "flop".
Speaking ahead of this weekend's fixture, Hughes said: "I left under something of a cloud.
"At the time I made the decision to leave because, given what I knew and what I thought was going to happen in the future, I couldn't commit to a new contract.
"I made the decision to leave but, with hindsight, it was probably the wrong decision.
"When I was there I had a few doubts over what kind of investment would be made available to strengthen the team. I interpreted that as maybe the club didn't want to keep on progressing.
"Obviously, almost immediately after I left they started investing in good players and spending some money, so I probably got that wrong.
"I don't think I have got anything to prove there. I am looking to go back there with my team now, which is Stoke, and do well. We need to get back on track."