Sixty may be the average retirement age, but Florence "SeeSee" Rigney can't see why.

Well, that's not entirely true. She did officially retire at age 67, but it lasted only five months.

As she explained to NBC affiliate King5, "I stayed retired for about five months, then I came back, and here I am."

Courtesy Sheri Morris

Today, at age 90, she's the United States' oldest practicing nurse, still wandering the halls of Tacoma General Hospital, setting up the operating room and making her fellow nurses smile.

Trending stories,celebrity news and all the best of TODAY. This site is protected by recaptcha

"She runs circles around all of us," Sheri Morris, assistant nurse manager, told TODAY.com. "She's a wealth of wisdom and knowledge, and we absolutely love her."

It was Morris and her director, Paula Swanson, who first had the idea to throw Rigney a surprise birthday bash. They put their heads together and realized that Rigney had taken the day off for her birthday on May 8, so they decided to have the celebration on the 7th.

"We had to do something," Morris said. "She'd had over six decades of service at the hospital. How could we not honor that?"

Courtesy Sheri Morris

What's more, Rigney — whose childhood nickname has stuck over all these years — hasn't changed stations since 1946, when she began her career as a student nurse at Tacoma General School of Nursing.

"She always knew she wanted to be a nurse," explained Morris. "Over the past almost-century, she ended up in a few different places in the U.S., and at times drifted away from Tacoma General Hospital to spend time with her husband or kids for a year or two, but she always came back here."

Morris has become quite the authority on Rigney's story.

"I came up with the idea to write to the governor and send along her bio, so that he might consider honoring her for her service. So I needed to get some of the facts from her," said Morris. "I asked her for some information, telling her that I just wanted to share her story with a local organization."

"She came back to me with 17 pages of handwritten notes, dates, and exact months," she added.

In the video above, posted on YouTube after the surprise, Morris points out that all the hospital "bigwigs" were in attendance on the day of the surprise, including the CEO, who handed her a bouquet of flowers (to complement the tiara and sash she'd already been given). Rigney's children even arrived for the surprise, and a majority of the hospital staff came out to celebrate her big day, too.

And Morris' letter to the governor was a success. SeeSee received a birthday note from him honoring her for her achievements.

"I can't believe it," SeeSee says toward the end of the video. "90 years ago, I came into this world. And here I am."