How to know when to move on and preparing for a new industry?

Another great question asked in the career planning AMA was:

How do you know when it is time to move on?
any tips on preparing to test in an industry you have never worked in before?

Which Bruce responded to with

By the time you’re asking the question, you’ve probably decided. It took me blinkin ages to move because I had good friends and a lot of opportunities for learning at my old place, but no opportunities for meaningful progression of my career.

I just moved industries, and a lot of testing skills are transferable but I do wish in hindsight that I had done a better reccie of the products and competitors. The first month would have been a lot easier if I had just sat down for a week and read the documentation on the website, all the promo material for the product, and how the company fares compared to other people who offer similar services.
Before starting I did ask my new manager for a list of topics he thought were most important to learn about for people who don’t know anything about the product. He sent some articles about design patterns we use a lot, as well as things to do with our tech stack and the product in general

I would definitely recommend switching industry every now and then though, it is invigorating!

Have you thought about the signs that it’s time to move on? What did you do to prepare yourself for testing in another industry when that time came?