Proofs give 100% certainty. They are rigorously reasoned according to some model. If the model is true, then the proof is true.
We need proofs, but alone, they are not enough. More accurately, they are but the discrete building blocks of knowledge.
Rather, those who create know how to construct networks of heuristics, each distinct and memorable. Each of these heuristics are like little shoots poking out of the soil. Each one visible from the surface of the soil, Each one easily traceable to it's roots in the network, None hiding the fact that it shares its space in the soil with other (likely related) shoots.
Have faith in your heuristics. And keep the sun shining.