I did as well, but didn't call it that.
When I was financially ready to leave my job, I stayed a while longer. About 2 years. The forcefield of trusted colleagues, interesting work, great pay and great benefits was strong. My FIRE plans were vague.
When I felt emotionally ready to leave my job (and a little burned out from some big projects), I pulled the trigger. I was 53. I launched into all sorts of activities that had been starved for time - spent more time with family, got way more fit, put in a great garden, and started volunteering. This played out like a sabbatical in the sense that it enabled me to gain perspective and fully separate from work. It also pressure tested some of my prior planning.
About 6 months later, it started playing on my mind that the option of doing consulting in the future or going back to employment would close in a few years if I kept on the FIRE path. It wasn't that I wanted to work again, just got the willies about closing off the option permanently. About then, my former boss called me about some work, which I turned down even though it feels great to be needed. Then I called back...so that I could have the following experiment: if I configured my work conditions so that they were perfect for me, would I want to continue working? Or would the pull of retirement overcome all?
I asked for and received part-time, narrow scope of work, highly flexible hours and location, and limited travel (along with former pay levels, interesting work and great colleagues). If the most perfect work assignment was no longer for me, my confidence level in my former decision would go to the sky. And it did. Without the break, I wouldn't have had the perspective to design that path.