A year on, the former world number one believes things could not be more different as he begins his 2014 campaign buoyed by renewed confidence in his game and recent engagement to tennis star Caroline Wozniacki.
"I feel like I'm much better prepared heading into the first event of the season than I was last year," McIlroy said ahead of the Abu Dhabi HSBC Golf Championship, which gets under way on Thursday.
"Things are really looking good. I'm in a really good frame of mind and feel like I've built a lot of momentum at the back end of last year and am going to try to continue that into this season.
"Last year there was a lot of instability and I feel like I'm starting this year on a different sort of platform. Everything feels like it fell into place and I can just focus on my golf."
McIlroy's debut with his new clubs got off to a bad start here last year, consecutive rounds of 75 leading to a missed cut and being followed by a first-round defeat to Shane Lowry in the Accenture World Match Play.
He then walked off the course during the second round of his defence of the Honda Classic and initially told reporters he was in a "bad place mentally", before a statement issued by his then-management company blamed pain from a wisdom tooth for his withdrawal.
McIlroy did finish second in the Texas Open the week before the Masters, but was 25th there and 41st at the US Open, where he broke a club in frustration.
He also missed the cut in the Open at Muirfield and labelled his own play "brain dead", although that experience did at least prove somewhat of a turning point in the season.
"From a professional standpoint, 2013 was disappointing," the world number seven added. "But as a whole, 2013 was a great year personally for me and I'm excited to start 2014 and get back to playing the golf that I know I can.
"The biggest frustration was probably at the Open. I had never missed the cut before and anything I was trying to do to the golf ball I couldn't. I was putting into bunkers, I was doing all sorts of stupid stuff.
"I was low on confidence and that's something I don't usually struggle with. I played with Phil (Mickelson, the eventual winner) the first two days and it completely demoralised me because he played so well. If you were even a slight bit off it made you look silly at times. I was a long way off and it made me look even sillier.
"I needed to go back to the drawing board and identified a few things in the swing, a few things I could do mentally on the golf course and from there it was just a process of trying to salvage something from the year."
A share of eighth place in the defence of his US PGA title indicated the two-time major winner was on the right track, while further work with coach Michael Bannon during a four-week break then saw him finish second in Korea.
"Something started to click and I just kept it going from there," the 24-year-old added. "Once you feel like something's there and you start to see some decent results, your confidence starts to build and it just sort of snowballs."
McIlroy indeed finished 6th in the HSBC Champions in Shanghai and fifth in the DP World Tour Championship in Dubai, before finally winning his first event of the year by pipping Masters champion Adam Scott to the Australian Open title in December.
Off the course, McIlroy admitted he had seen enough lawyers' offices to last him a lifetime as he became embroiled in two legal battles, but with one with former sponsors Oakley settled, he now just needs to resolve the other with former management company Horizon.
And the Ryder Cup star believes he has also finally settled on the right equipment as he looks to reproduce the form which saw him top the money list on both sides of the Atlantic in 2012.
"It was a distraction," McIlroy added. "You're thinking of other things when you really shouldn't have to. But it's the last year I'm ever going to have to go through something like that. I've learned from it and I'm smarter because of it. It's great that I've gone through it at this stage in my career and not 15 years down the line.
"There was loads of stuff going on around me and that didn't let me focus 100 per cent on what I needed to do. This year is the polar opposite. Everything just seems to have fallen into place nicely and I can just go out there and focus on my golf."
McIlroy intends to have a "fluid" playing schedule depending on results, but has revealed he will definitely play the Scottish Open at Royal Aberdeen the week before the Open at Hoylake, feeling he will benefit from competitive links golf rather than practice.