In the last fifteen years, there has been a significant shift from on-premise data centers to the cloud. This process was due to the perceived cost difference between the legacy on-premise data centers and the newer and shinier public cloud. Due to a renewed interest in privacy and data sovereignty, many organizations are returning to the on-premise with private clouds. For the success of such initiatives, it is fundamental to learn from the past and understand how a successful private cloud should be structured. I started working in 2004 when almost everything was on-premise, and I had a front-row seat to the migrations that occurred in this period thanks to my roles as a Systems and Solutions Architect. In this talk, we will recap the last twenty years of migrations to learn some key lessons, and then we will analyze what a successful private cloud would look like, which technologies might help, and which could be risky bets.