The more complete claim is that we understand the fundamental laws of physics as they pertain to everyday life. The qualifications are important. Fundamental be

The more complete claim is that we understand the fundamental laws of physics as they pertain to everyday life. The qualifications are important. Fundamental because being able to predict the interactions of a handful of particles doesn't automatically lead to visibility of the large-scale behavior. An example of this is protein folding: we know how proteins fold, but finding out how to get a particular shape basically requires brute-forcing the search space. Everyday life excludes dark {matter,energy} as well as quantum gravity and anything that requires the energies of large particle accelerators to probe.