I procrastinate a lot on hard tasks and usually it's because I don't yet fully understand the risks with each decision that goes into the design.

I think for younger engineers "fail fast" makes a lot of sense; there's not enough of a foundation of experience to tell right from wrong so the only way to learn is to fail.

For more experienced engineers, there's a greater sense of "I have a sense where this can fail; how do I design around that?"

It's not that a more experienced engineer will know exactly how it fails, but that there are modalities of failure that have been encountered so the goal is to design with some flexibility or optionality in mind. And sometimes, this just requires a bit of "gestation" or "percolation" before carving the path.

I think of it like an experienced sculptor sizing up a block of marble before making the first strike with a chisel. It's a kind of procrastination, but really, its a process of visualizing the path.