Try teaching an animal about our tech and ways. You get some success like monkeys/apes/etc using computers to communicate, silly pictures of squirrels on bikes, etc but there is only so much you can teach them. I think it we might have the same problem with actual "extra terrestrials."
Well humans do have an unusual will to learn for sake of learning. Other animals seem less interested in being so innovative, and their efforts are only ever as means to an end - usually a banana or seed or nuts or whatever. They don't learn and study for sake of academia.
If alien technology is literally unlike anything we've experienced, then we have no starting point, and no grasp of what we're dealing with. But the chances are we will. Alien technology will likely have 'innards' that we can disassemble, map and examine. By learning what bits are connected where, we get a sense of its structure and layout. We also have tests which we can subject things to - electron microscopes and things to see fine detail. If some stage does behave in a way we don't understand, at least we'd know that there is something there to learn. These are all things we can work with ; 'handles' we have on the alien technology; places our thoughts can spread out from.
For an alien technology to be truely unlike anything we've experienced, it would have to be composed of unconventional material. For example, humanity does not understand at all what is the nature of mind and consciousness. It is something we don't study or investigate, simply because we don't know where to begin. Some people cut up brains, and study electrical signals inside them, but that doesn't seem to get us any closer to understanding what mind and consciousness is. All they have are electronic circuits.
Alien technology might be a technology built upon mind and consciousness, and have an ambiguous relationship with matter. In the Starcraft universe they call it Psionics.
However, if they travel here in material starships, have material bodies, and are interested in us - biological material entities, it suggest some sensible limits on how different we can be. So their technology is more likely than not to be fathomable.
Perhaps that is the human strength, and what sets up apart from other animals?
That learning is our strategy, and if something is observed to behave in an unfamiliar way, we know that there is something there to learn.