How a complete human body develops from a single fertilized egg cell is among the deepest scientific questions. A crucial stage in this process is called gastrulation, during which the basic body plan is laid out and cells differentiate to the main lineages that will form the different organs. This stage cannot be ethically studied in human embryos and is also difficult to study in other mammals. However, it can be experimentally mimicked in a dish by confining human stem cells into disc shaped colonies. These will then undergo self-organized embryo-like pattern formation while allowing systematic quantitative study. This approach has been used by a small community of mostly physicists-turned-biologists to discover new principles of human development that challenge the existing theories of pattern formation. In my talk I will give an overview of this field, discuss how I ended up there after my PhD in theoretical high energy physics, and show some recent results from my group.