A bridge exists because somebody refused to accept the river as the end of the road.

Every crossing you use without thinking was once an argument with an obstacle everybody else treated as final. The river was genuinely there and genuinely in the way, and somebody decided the problem was the gap rather than the route, which is the difference between a dead end and a construction project. Obstacles get much of their authority from agreement.

Take something you have filed under impossible and state the actual obstacle in one specific sentence. Then find out whether anyone has solved that exact thing before, because they usually have. Borrow their method instead of starting from the river.