Having a rough day? Need a confidence-booster?

Listen to these pearls of wisdom from Mirjana Lucic-Baroni, a 34-year-old tennis star enjoying an improbable comeback.

After her once-promising career derailed and a long struggle to get back into the sport’s elite, she defeated 21-year-old Jennifer Brady at the Australian Open on Monday to reach the quarterfinals of a Grand Slam event for the first time in 18 years.

How’d she do it?

In an on-court interview after the match, Lucic-Baroni called herself a “tough little cookie” and spoke about how hard she’s worked. Then, she offered some advice to everyone else who’s going through some tough times.

“I will tell it to anyone struggling out there ― actually, I can’t say it because the TV’s here and I’m going to get fined, but...” she said.

“Oh go for it,” her interviewer pushed. “Go for it!”

That was all she needed:

“F everything and everybody, whoever tells you you can’t do it. Just show up and do it with your heart.”

Words to live by.