My first OpenStack install was on a bunch of VMs. Got that to run following the official documentation. Got enough people interested in it, that I was "allowed" to salvage whatever hardware I could find and put in a Rack.
Getting Neutron to work was a head first intro to networks and in the end I had to learn how to configure actual network hardware.
After adding Ceph on top of old spinning disk, watching them die one after the other and the cluster was still up with performance not worst than the IBM-Stuff we were paying for gave me warm-fuzzy feelings.
Thanks to Triple-O, Fuel and most of the other "installers" at that time I learned that - the "big guys" don't know what they are doing either ;-)
At the end of the day, it took the "mystical" out of the cloud, and for Junior me that was good - it also saved me from the path management wanted me to go: Sharepoint developer/admin.