Once I had a paid game project from a third party (who was a friend of my friend) who actually had the client. Either they gave me a 2-month deadline or I gave them one to complete the project, I don't remember it correctly.
I knew I could deliver it in 2 weeks or less, so I got busy doing other projects.
Long story short, client ran away because I didn't communicate with the third party the whole time through my friend (who I kept it in the dark) and delivered the first playable version not according to the exact requirements (how could I because it was not the final version).
I never heard/read about Parkinson's law at that time, I now understand I was just filling my available time with other stuff.
I knew I could deliver it in 2 weeks or less, so I got busy doing other projects.
Long story short, client ran away because I didn't communicate with the third party the whole time through my friend (who I kept it in the dark) and delivered the first playable version not according to the exact requirements (how could I because it was not the final version).
I never heard/read about Parkinson's law at that time, I now understand I was just filling my available time with other stuff.