I’ve been doing this for 28 years. Definitely pace yourself. When raising a family and making money I’d work nights, weekends, etc. probably the worst time as that time should have gone to family.
I don’t think it’s arrogant but I’ve gotten to the point where no matter how difficult the problem to be solved is, I’m confident I’ll figure it out. Just realize you may have to step away and come back less myopic. That helps with the stress that can arise when it feels like it’s never going to work.
One also realizes some of what they know, a framework for example, has a shelf life and may be useless knowledge in 3–5 years. You gain confidence that you can learn whatever is new and needed and keep going.