O’Sullivan, who has won the tournament seven times, beat fellow Englishman Robert Milkins 6-5 in York on Thursday but was less than impressed with his performance.
"I thought he deserved to win," O’Sullivan told BBC Sport. "I couldn't feel anything, I was just all over the show. I haven't got a clue any more, I don't understand how this game works.
"I had to grind out another win for my sins. It's a crazy game, it still torments me after 30 years.
"I gave up a long time ago, I just keep turning up and stinking out gaffs. I stunk it out today and I'll probably stink it out tomorrow."
O’Sullivan criticised the World Snooker Tour earlier this year after five of its players competed in an exhibition event in Macau and threatened to leave the sport after facing disciplinary action.
"Mentally it's hard for me. I'm not going to kill myself out there, but I still want to play," he said.
"I just can't be bothered any more. I just don't want it bad enough, that's the problem.
"I'm having to dig deep, whereas when I was younger I didn't have to dig deep and I was so hungry.
"Now I don't really care any more. Competitive sport is really hard, it's not always about how good you are, it's about how much you want it."
Milkins told BBC Sport: "I just played a really poor decider, I could have won that but I'm chuffed I've just stuck in there because I always roll over against Ronnie.
"I put a fight on, but I'm really disappointed."
