Impossible or difficult?
Do you say something is impossible simply because you think it is difficult? Do you use the word as an excuse to be lazy? Why? Does doing it take you out of your comfort zone? Are you afraid of change? Or have you just learned to react to new things like that? We all have opinions that are automatic and we often don't even realise this.
Pay attention how often you automatically say something can't be done. Are you really of that opinion? Did the thought of doing that "impossible" thing pop up for a reason? Is your subconscious trying to make you pay attention to a new path you could follow?