Impossible means no matter who does the task or how it's done, the set goal cannot be reached.
Such as pulling a TV character through the TV into your living room.
The antonym possible means that the set goal is possible, most likely by numerous parties.
Most people say "That's impossible" without knowing all potential parties and possible ways to achieve the specific goal, and most likely the goal can be achieved, just not in ordinary terms.
A lot of people ignore clearly impossible things, such as killing yourself and expecting to be a martyr of some sort and getting rid of their problems in doing so, when it truth it creates a lot, it's insanely selfish, and who knows what happens when you die? Oh well this isn't religion talk
Dave: No you're an idiot, you'll die for sure.
Rob: It's impossible to die!
Ryan: Dude it's impossible to finish all of this homework.
Mom: Just do it, you'll finish it.
Rick: That's so impossible to take a toaster and eat it without removing the parts
Dave: Actually it is impossible, good job.