Are we alone in the Universe? Since the confirmation of the first planets outside our solar system in the 1990s, we have made tremendous progress towards answering this question. Yet, the confirmation of a true Earth-analogue still evades us. On top of this, if we are truly to understand the origins of life in the cosmos, we must also create a complete picture of planetary formation, evolution, and habitability. However, each of these aspects necessitates a detailed knowledge of Sun-like stars. This is because we study exoplanets indirectly by analysing their much more luminous host stars. For example, most planet confirmation relies on the Doppler wobble of the host star, induced by the presence of the planet. Moreover, we can learn about a planet's dynamical history from mapping its projected orbit as it transits its host star. Hence, if there are inhomogeneities on the stellar surface, they can impact planetary interpretations and even completely swamp the signals from rocky worlds. In this talk, I will discuss how we confirm and characterise planets outside our solar system and how our knowledge of their host stars poses a fundamental hurdle we must overcome on the pathway to rocky, temperate worlds.