The 21-year-old from Welwyn Garden defends the Portugal Masters title this week, but has to go back over five months to the last time he survived a cut.
Even a 65 at St Andrews last Saturday - his lowest round since he won at the Oceanico Victoria club last October - could not save him from yet another early exit.
At 123rd on the money list Lewis would be facing a first trip to the qualifying school but for the fact that his stunning victory - achieved in only his third event after leaving the amateur ranks - earned him a two-year exemption.
He told European Tour radio: "It's a shame I'm not playing as well as I was this time last year.
"It's disappointing that I won't be up to my A-game. I've had some good rounds, but I haven't been able to put two rounds together.
"I was holing a lot more putts last year. It's frustrating because I know I am capable of doing it and I've improved on most of the areas I've wanted to, but it just has not come together.
"I'm frustrated with myself for not performing to the level I expect.
"I did expect a little bit of a dip in my career, but my game isn't at the level I thought it was going to be.
"I'm disappointed and I wish I had done better - of course I do - but luckily I've got next year."
Lewis's victory earned him £335,000, whereas his 2012 winnings on the circuit total £125,000.
"In my eyes it's not really about the money - I've never really been interested in that. It's about playing golf and trying to improve," he said.
"Unfortunately it's been an expensive year because I've missed so many cuts (13 in Europe, one in America) travelling all round the world staying in nice places.
"I've learnt a lot, but I'm also disappointed I haven't turned that into performance."
Martin Kaymer and Francesco Molinari are the two members of Europe's Ryder Cup team in the field and, perhaps not surprisingly, they have been paired in the first two rounds with captain Jose Maria Olazabal.
Olazabal put them in the bottom two positions in the singles when his side were four points behind. After a spectacular fightback Kaymer beat Steve Stricker to guarantee the cup stayed in European hands and then Molinari's half with Tiger Woods gave them victory in the match.