Why Isn't Bloch's Theorem Reduced to Unity?

toqp
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This is not any homework problem but just something I don't understand. The Bloch theorem states that
\psi(\textbf{r}+\textbf{R})=e^{i\textbf{k}\cdot \textbf{R}}\psi(\textbf{r})

Now the k is a vector in the reciprocal lattice (usually in the first Brillouin zone), which is defined as the set of vectors K that satisfy
e^{i\textbf{K}\cdot\textbf{R}}=1

Now, if k points to a point in the reciprocal lattice, then why isn't the Bloch theorem
\psi(\textbf{r}+\textbf{R})=e^{i\textbf{k}\cdot \textbf{R}}\psi(\textbf{r})
just
\psi(\textbf{r}+\textbf{R})=1\psi(\textbf{r})?
 
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AFAIK, k is not limited to a reciprocal lattice vector. I think that would only be for standing waves. The complex phase gives the wave a direction.
 
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