Dust is pretty inescapable. Dust can even be from dead skin off of you. You're always surrounded by particles in the air, some you can see, some you can't see. The air is almost never 100% clean. But that doesn't mean that upkeeping cleanliness and seeking things like humidifiers, filters for A/C-Heater-Furnace is all for naught. They will help and keeping a light schedule as to how much you clean helps too.

I know, dust really sucks and can give you the feeling of 'why bother' when it's just going to come back and collect layers in a matter of time. But, you can at least slow it down.