One embodiment of the present invention is a unique gas turbine engine. Another embodiment is a unique gas turbine engine high speed rolling element bearing system. Other embodiments include apparatuses, systems, devices, hardware, methods, and combinations for gas turbine engines and high speed rolling element bearing systems for gas turbine engines. Further embodiments, forms, features, aspects, benefits, and advantages of the present application shall become apparent from the description and figures provided herewith.