1. Get supplies.

2. Return some supplies and replace because they turned out to be damaged/the wrong size/whatever.

3. Go back for more because you counted wrong/ they didn't cover as much as the manufacturer stated/whatever.

***rinse and repeat***

Then that repaired problem uncovers another. It's exponential.

Though after 20 years, we've given up on some and let others accumulate. The next burst of projects will be dealing with all the electrical bungles a previous DIY owner made. Too many damn light switches don't do anything anymore.