The dispersion relation of a free electron in vacuum is k2/2, the dispersion relation of an electron in a solid may be arbitrarily complicated. In my talk, I will discuss the consequences of this simple statement for high-harmonic generation (HHG) in solids. In brief, the laser-driven electron dynamics becomes much richer in solids, a treatment analogous to the one by Lewenstein et al. for gas-phase HHG becomes much more involved, and anomalous electron velocities and topological effects are not even understandable by just looking at the dispersion relation alone. I will introduce a theory of HHG in solids that is applicable to all systems governed by 2x2 Bloch Hamiltonians. The theory is applied exemplarily to the Su-Schrieffer-Heeger chain and the Haldane model in intense laser fields, which are prime examples for topologically non-trivial “fruit flies”.