The Inside of a Neutron Star

In many cases there are actual similarities. Waves appear everywhere because wherever you see a -d^2 x over d^2 t, you get waves. Explosions happen at many scales because wherever you get an exothermic reaction that makes itself happen faster you get an explosion. As the article itself says:

"Because they are made of a water-loving and water-repelling layer sandwiched together, their interactions with a watery environment make them self-assemble into the spaghetti- and lasagna-like structures known as endoplasmic reticulum,"

where you get two things that attract and repel in the same way as fats and water, you get characteristic shapes. Many similarities aren't just visual, they really do represent underlying similarities in the relevant processes.

"If intelligent creatures existed that were built out of magnetic field lines in the Sun, or variations in density in the interstellar medium, we might never recognize them as life, and they might never recognize us."

Life needs to be able to expel entropy faster than the environment jams it in, or it isn't life anymore. It is very likely that nothing can possibly live in a star, because entropy is getting jammed in to every cubic centimeter pretty hard. Interstellar-medium-based life has the problem that it must necessarily interact multiple orders of magnitude more slowly than Earth life because all of its components are much more separated and it has the same speed-of-light limits as our biochemistry has, so even if it somehow overcomes the problem that having complex, information-processing-capable structures that function without chemistry (to a first approximation, the interstellar medium is a tiny puff of hydrogen gas) doesn't seem possible with just gravity, from its point of view the universe is probably too young to even have the initial life form, to say nothing of the fact that on that time scale, the interstellar medium is constantly getting stirred up by things.

I'm no scientist but I wonder if there isn't a TON of things that we've just been assuming to apply universally.

If all matter in a solar system is largely formed from the same cloud or nebula, then it must limit what we can learn from our sun and neighboring planets, and asteroids or comets.

Other systems may have radically different composition and occurrences of different elements and their isotopes, maybe effectively having different periodic tables, so to speak. The size, gravity, color, radiation of a star may have great influence on how planetary matter forms and interacts with each other; maybe water will have different observable properties in such different systems.

As for life; we have yet to catalogue the complete scale of life on Earth alone. We still get surprised by discoveries like Tardigrades and deep sea creatures. I'm sure the Infinity of the universe has even more surprises in store.

There may be creatures flying around in dense nebulas, not bound to any planet.

There may be rogue planets drifting through interstellar darkness with no sun to orbit, but still supporting life under the surface near their warm cores.

There may be little asteroids inside gas giant planets, effectively making tiny solid worlds inside a sea of different gasses.

As for life that develops industry; just look at the bodies of octopuses and what they're capable of. It's a shame they have such short lives and hostile environments to contend with, though. For now.

Also, it is perfectly possible to create electricity without being intelligent (the electric eel, for instance).