The nature of dark energy is one of the great mysteries of our Universe. Unlike with dark matter, we run into problems when we use conventional particle physics intuition to reveal the microphysics of dark energy. In my talk, I will highlight two a priori unrelated aspects of dark energy model building: First, dark energy models are often very sensitive to unknown high-energy physics. This goes under the name of the cosmological constant problem and has plagued theorists for the better part of a century. Second, a recently proclaimed discrepancy in the predicted value of the expansion rate of the Universe today seems to indicate the presence of a new phase of dark energy in the early Universe. I will argue that both observations can serve as a guiding principle in our efforts to understand the fundamental nature of dark energy. In keeping with the informal character of the Scientific Fika I will also use the opportunity to take a personal look back on my path as an early career scientist.