Comets are considered primitive left-overs from the era planet formation. Most comet science questions therefore revolve around whether observed properties are primordial, i.e. representative of conditions during the era of planet formation, or whether they are caused by subsequent processing. Comets may also have delivered water and complex molecules to Earth and other planets in our solar system. Finally, the discovery that our solar system is frequently visited by interstellar comets places comet science at the forefront of astrobiology. This talk will take attendees on a tour of what we know about comets, what mysteries we need to solve, and how future spacecraft and telescopes could help us answer our questions.