I had a lot of trouble getting into PowerCLI. I knew some of the basic commands, but I never used it to do anything productive. The biggest site I managed had 150 VM’s, and I could do most tasks quickly through the vSphere client.
Since then I’ve changed jobs, and now there’s thousands of VM’s to manage!
Coming into such a large environment, I’ve had to learn Powershell and PowerCLI out of necessity.