@Setanta,
You need to think a little deeper than that Setanta.
We and "the world" are inextricably bound together. So although for pragmatic reasons we project the concept of "an external world" (what you might call "objective" or "external reality") and we reify (aka construct) that concept with socially acquired language, what constitutes "reality" is always a dynamic interaction between internal and external states.
A
simplistic analogy is one of a board game like "Monopoly" in which the state of the board (internal) interacts with the state of the dice (external). The dice state has no significance in its own right except with reference to the board. If the board is receptive, the dice state can change the board state, such that another dice state may become significant, or indeed the original dice state might lose its significance. By analogy, external states of "the world" have no significance of their own (there are no
Dings-an-Sich) -except by reference to dynamic physiological states of the observer, or sociological states of the observer's consensus group. Evidence
abounds from comparative biology, cognitive science and anthropology, that this dynamic interaction both operates and can be manipulated.
(For further extensive discussion of this please refer to my posting history on this forum)