One way to cap the cognitive load of adding and maintaining comments is to limit them to explain why a piece of code does what it does, rather than how. Rely on the fact that the how is self-documenting to other programmers who may need to maintain your code later (including you), but the why is not always so.

Eg, were other options considered and this one chosen? Why? Is this piece of code non-standard or particularly clever? Why? Is this piece of code more complex than it seems like it needs to be? Why? Does this piece of have non-local dependency that may not be obvious at first glance? Are there security concerns with this piece of code which are non-obvious to a novice or an outsourced worker? Etc.

There's the old saying, "since debugging code is more difficult than writing it, then if you write the most clever code you are capable of, then you are by definition incapable of debugging it". Pretend you're explaining your code to future you who has forgotten why you did what you did and isn't clever enough to debug it.