In my talk, after an introduction to the field of quantum optics with cold atomic gases, I will be presenting a number of experiments that demonstrate that the versatility of light-matter interactions in a cold atomic ensemble, and how this enabled us to access seemingly unrelated physical phenomena. These observations range from the creation of a non-Hermitian quantum interface between single atoms and light, to the simultaneous manipulation of the spatiotemporal wavefunctions of single photons, and finally to the induction of fictitious magnetic fields by spatially engineered light for quantum storage.