What do you wish you knew about your fitness career earlier?

What do I wish that I knew earlier in my fitness career? To focus more on the business and relationships with my clients than on exercises, music and choreography. I always felt I had to come up with something new, but over time I realized I was more likely to want to change things up than my clients. When I had a fitness studio (30 years ago!) I should have spent more time on marketing and less on new music and routines. Of course that is also the part I still love to do, so it is easy to spend too much time on that.
That said I believe I never felt “stuck” because I was always so attuned to what is new, and to learning more. That is what keeps me interested and fresh, so I have never really felt stuck.