Jennifer Nettles has had almost two decades of unprecedented success in country music. She's part of the insanely popular duo Sugarland, but also has a powerful solo career, which is picking up major steam. But when asked what she's most proud of, she gives a surprising answer: motherhood.

In the wake of her son Magnus' first birthday in December, Nettles reflects on being a mom. "It is like the friggin’ Peace Corps, man -- the toughest job you will ever love!" the 'Stay' songstress insists.

"It is the most challenging … and it is the most rewarding," adds Nettles. "They go hand-in-hand, and it is both. I love it. There is no part of your life that isn’t touched by it."

Nettles says the biggest challenge in her life since Magnus has been keeping up her energy and getting rest, which we're sure she'll need as she gets ready to hit the road in February in support of her solo album, 'That Girl,' which debuted at No. 1 on the country album charts. We're also guessing that she'll need even more energy as Magnus enters his toddler years!