I visited Abercrombie & Fitch for the first time in 12 years. I was shocked by how much it's changed and now I see why Gen Z loves it.

• I shopped at Abercrombie & Fitch's new store on Fifth Avenue in Manhattan. 
• I was surprised by how sophisticated everything was, including the store's design and the clothing.
• As millennials grew up, so did the brand. It sells suits for the office and dresses for weddings.

I don't think I've been in an Abercrombie & Fitch store since I was in high school. So I was surprised to see the company's new location on Fifth Avenue in Manhattan — it felt like a different brand.

Abercrombie has quite literally grown up alongside millennials. In place of logo-emblazoned tees and polos we once wore with pride in school hallways are crisp linen suits for the office and elegant satin gowns for attending summer weddings. 

But it's not only for millennials — a recent study by Earnest found that Gen Z's spending at Abercrombie was up by 44% from January to June. 

The company says this shift in aesthetic has contributed to the brand's newfound popularity and success. Abercrombie surprised Wall Street in August by reporting a 16% year-over-year increase in second-quarter sales, to $935 million, and posting net profits well above expectations. CEO Fran Horowitz said the company's playbook was working and "we are no longer a jeans and T-shirt brand."

"This is truly the most powerful brand transformation that I've seen in my career," Horowitz told analysts in May. "By listening to our customers and putting them at the center of everything we do, we are delivering product, voice, and experience that are tightly aligned and continue to resonate."

That brand transformation was evident during my recent trip to Abercrombie's store.