Don't forget to live a little, man.
It's good to have discipline, it's good to be stoic. But it's also good to indulge every once in awhile and then really pay attention to how it makes you feel. Was it worth it? Was it everything you wanted it to be? Is there enough of a contrast to even make it an indulgence?
Was it, at the very least, a pleasant diversion from your self-imposed rules? We all need that. Otherwise we begin to imagine our lives in italics, so serious, like you've mentioned before...
Using this system of checks and balances, you've found that some of your old indulgences don't really do it for you the way they once did: smokin' and drankin', for example. And that some new, weird ones, like fermented foods and saunas(?) are an unanticipated pleasure.
This is age. Refinement. Evolution. But you would miss it if you weren't checking in from time to time.
You want constant improvement, right? Measurable, tangible progress in italics! But not at the expense of the crippling rigidity that is so often a symptom of this mindset. Ebb and flow, fail and achieve, feast and famine. This is the natural way of things. Let it be with you.
Beware of your own intolerance and boundaries, and whether a deviation every so often doesn't make your challenges more bearable. More sustainable. More, as your hero, Marcus, would say, reasonable.
Make things happen and use Archimedes' lever and attempt big things while you are awake. Do that.
But don't forget to live a little, too.