But the 29-year-old Belgian managed to say farewell to singles on Wednesday after a 7-6 (7/4), 7-6 (7/5) loss to British teen Laura Robson in the US Open second round at the same Arthur Ashe Stadium where she won three titles.
“The first hour after the match there was still disappointment and a little bit of frustration,” Clijsters admitted. “Still had that routine of going through the match and trying to figure out how to do it better next time.
“After talking and thinking about the retirement in singles, I’m happy. In the last two years, it has been up and down. I’m happy that I stuck through it and I was able to live a lot of these emotions I’ve had.
“Proud of myself that I was able to do that.”
Former World No. 1 Clijsters retired for the first time in 2007 to give birth to daughter Jada with no plans to return, feeling she had accomplished her Grand Slam dream with a 2005 US Open title.
But she returned in 2009 and with only two tuneup events captured the US Open title, then defended the crown in 2010 and added a 2011 Australian Open title just for good measure.
“It has been an incredible journey and a lot of dreams for me have come true because of tennis,” Clijsters said.
“For me to have been able to have been a part of women’s tennis, and on top of women’s tennis for so many years, it has been a crazy rollercoaster.”
Finally looking in the rear-view mirror at her career, Clijsters’ thoughts drifted to where it all began.
“I think about when I first stepped on tour and met Steffi Graf and Monica Seles,” she said. “As a little girl, I got tennis racquets under the Christmas tree and outfits of Steffi Graf and Monica Seles and I would want to wear them to bed I was so excited.
“All of a sudden when you’re 15, you kind of get thrown in the spotlight. You go through puberty in the spotlight. You have your first boyfriend in the spotlight.”
Clijsters wants to use her experience to help the next generation of young tennis hopefuls live their dreams the same way she did.
“I will always look for challenges,” Clijsters said. “Even in life without tennis at a high level, I’ll always be involved in tennis. I’ll always try to give back to others what tennis has given me.
“I look forward to kind of that next chapter, where I can help younger kids and girls who would like to be in our shoes and live this kind of lifestyle.”
Through 41 career singles titles, the moments Clijsters most fondly recalls are the ones where she was battling with every swing and stride.
“Those are definitely the moments that I enjoyed the most, your back against the wall and still find a way to come back and play well,” she said.
“Those are definitely moments that are fun to have, fighting for it when you’re not maybe playing your best, but still finding a way to battle through it and play hard.”
Clijsters became the first mother to win a Grand Slam title since 1980 and that achievement is one of her proudest.
“I feel proud that I was able to win a Slam as a mother, just because I know how much work it took after I had Jada to get back physically, tennis-wise, and mentally to get back into the sport,” Clijsters said.
“There were moments that it was hard. When I first started coming on tour it was hard to find balance. When I was home I was still working out, practicing hard, but I was 100 percent mom.
“With our lifestyle I’m maybe more with her than parents who work from 9-to-5, but as a parent you always feel like you miss out on things or a little bit guilty and want to do better and be the perfect parent.”
“A couple times this week, she was like, ‘Why don’t you come with us to go for a walk?’ I’m like, ‘Mama is almost done. When I’m done I’ll be there and I’ll do all those fun things with you.’
“I think she’s going to be excited to have her mom around on a more regular basis.”