I've noticed recently how often-present is the idea of magic not requiring an origin or a source.

Your typical fantasy never goes into details of how it works, either: it just does, and all we have to do is think about it, wave a targeting device or chant an arcane word. How audacious of us to assume that a few individuals can wield powers of theoretically-limitless might with not much - or nothing - but their minds while the rest ought to do no more than marvel and awe at the thing shining bright in unnatural colors.

To me, it doesn't make sense. Saying that magic just works is like saying that hammer just propagates the nail further into the medium, despite the fact that you are actually required to produce certain motions with no less than the necessary amount of strength for it to happen - and that's not taking into scope the idea that the nail might be deep underwater, which will require even greater strength application, and breaking the water tension if the tool is above the surface, and keeping the pressure on the hammer constant so that it won't stop due to drastically increased pressure and density...

You get the point. Many magical systems are as simplistic, which can be a good thing if your intention is to tell the story rather than tell about the world, or if the former dominates the latter. I can't say, however, that fleshed-out systems aren't necessary or aren't worthy of the time and effort; they do, however, appear to be a work of a higher skill level of worldbuilding - which I suspect to be the main reason for most of the fantastical works not to include it.

And - alright, suppose we've described its origin, be it a deity, an other entity (like the Weave in Faerun - I think that's its name), a completely different plane of reality (or outside of it) that translates informational chaos which allows you to bend the matter and energy inside for a bit of time, a law of nature (or, indistinguishable from it, a synthetic tool so natural to the world by the time the people we watch arrive that they don't see it as any foreign)... Describing how it works - precisely, how it flows from its origin into the reality - becomes a difficult matter.

Handwaving it by saying that our mind is powerful enough to "transfer" the magical energy is the most common method. Some put their money on rituals, which is saying "I beg my god to do my bidding" - again, incredibly audacious of us. Some allow their magic wands (whatever those might be) to do their bidding, instead, by making it excrete some sort of magical energy for the same purpose. That's a lot of energy, isn't it? It never seems to run out. Why didn't we appropriate it for some powerful engines to power the lightbulbs of the world forever?

So, what can we do about it? Is there a way to make magic sound plausible without breaking immersion or suspension of disbelief? In other words - can we describe some sort of immensely-powerful reality warping that would still make sense to us who don't live in the fictional world?