That falls on one, empirical, fact, which is that the world and the universe are both provably much older than we are. Nature, with all its' colours, sounds, smells and textures existed long before we were here to take cognisance of them The creatures that evolvedin the world were aware of it to the extent that they were capable of, and evolution (however it works) has tended toward extension of that awareness. The human mind is a result of one aspect of evolutionary development across various species of hominids hominins and humans. The tragic loss of other human species leaves us unable, as it were, to compare notes with them on our perceptions of the world. We are left with observing the reactions and behaviours of other animals. Their type and degree of consciousness may differ from ours, but the fact that, like us, they walk round solid objects, take note of sounds, etc, indicates that these things have an existence outside our minds. Or that the same things exist in theirs, which of the two is the more unlikely.

Besides, if reality is not independent of the mind, why is life so damned difficult at times?