Yes, Stoicism teaches you that you don't have (at least ultimate) control over the world. But it does emphasize that you have control over yourself. You internalize your goals: Instead of "winning the tennis championship" it's "be the best player I can possibly be despite circumstance".

There are some things you really cannot change. We can change more than we used to, but not everything. Stoicism helps.

And we also change things we don't need to change. We chase after things that bring us no happiness. By allowing you to be happy with what you have, stoicism lets you seek those things that truly matter.

For instance, I work with Enterprise Software but not with cars. Perhaps being Stoic towards my material possessions( such as liking my Honda and stop looking at the Maserati I don't need) while still driving towards improvements in the areas that matter, such as my relationships (family, friends, strangers) and career (software, etc)?

We don't have the resources to keep all modern humans in the manner to which those in developed countries have become accustomed.

Since 'improvement' is so often a subjective quality the stoics may perhaps suggest you rebase what you consider to be self improvement.

What if one could find a way of being happy regardless of 'self improvement' drives?

If happiness is the objective and you can be happy without changing your environment, even if changing the environment is trivial, what's the difference?

My mind keeps coming up with generalizations all the time. For example, "the more space you have for your family, the less valuable time together you spend". Needless, useless generalizations like this about just about everything. So I've formed a mental habit of just pausing and asking "really?" .. and soon these just go poof.

In other words, I automatically question the validity of any concept I construct. This way, I'm free to stick to one temporarily and have no qualms about abandoning concepts that aren't valid for me.

The nice thing about Derek's post is that he's just posing the question and leaving it to the reader to ruminate on what answer would mean to them. The skill to pick up here is to ask these kinds of questions ... like all the time.

I think "changing the things you can" (as Niebuhr once put it) is precisely the second half of the stoic idea. In fact, not changing things that by rights should be changed runs contrary to virtue, which the stoics held as the chief -- and indeed, the only -- true good.