<p style='text-indent:20px;'>In this paper we study the continuity in initial data of a classical reaction-diffusion equation with arbitrary <inline-formula><tex-math id="M2">$ p>2 $</tex-math></inline-formula> order nonlinearity and in any space dimension <inline-formula><tex-math id="M3">$ N \geqslant 1 $</tex-math></inline-formula>. It is proved that the weak solutions can be <inline-formula><tex-math id="M4">$ (L^2, L^\gamma\cap H_0^1) $</tex-math></inline-formula>-continuous in initial data for arbitrarily large <inline-formula><tex-math id="M5">$ \gamma \geqslant 2 $</tex-math></inline-formula> (independent of the physical parameters of the system), i.e., can converge in the norm of any <inline-formula><tex-math id="M6">$ L^\gamma\cap H_0^1 $</tex-math></inline-formula> as the corresponding initial values converge in <inline-formula><tex-math id="M7">$ L^2 $</tex-math></inline-formula>. In fact, the system is shown to be <inline-formula><tex-math id="M8">$ (L^2, L^\gamma\cap H_0^1) $</tex-math></inline-formula>-smoothing in a H<inline-formula><tex-math id="M9">$ \ddot{\rm o} $</tex-math></inline-formula>lder way. Applying this to the global attractor we find that, with external forcing only in <inline-formula><tex-math id="M10">$ L^2 $</tex-math></inline-formula>, the attractor <inline-formula><tex-math id="M11">$ \mathscr{A} $</tex-math></inline-formula> attracts bounded subsets of <inline-formula><tex-math id="M12">$ L^2 $</tex-math></inline-formula> in the norm of any <inline-formula><tex-math id="M13">$ L^\gamma\cap H_0^1 $</tex-math></inline-formula>, and that every translation set <inline-formula><tex-math id="M14">$ \mathscr{A}-z_0 $</tex-math></inline-formula> of <inline-formula><tex-math id="M15">$ \mathscr{A} $</tex-math></inline-formula> for any <inline-formula><tex-math id="M16">$ z_0\in \mathscr{A} $</tex-math></inline-formula> is a finite dimensional compact subset of <inline-formula><tex-math id="M17">$ L^\gamma\cap H_0^1 $</tex-math></inline-formula>. The main technique we employ is a combination of a Moser iteration and a decomposition of the nonlinearity, by which the interpolation inequalities are avoided and the new continuity result is obtained without any restrictions on the order <inline-formula><tex-math id="M18">$ p>2 $</tex-math></inline-formula> of the nonlinearity and the space dimension <inline-formula><tex-math id="M19">$ N \geqslant 1 $</tex-math></inline-formula>.</p>