Before boats and printers there were engines. Years of mechanic work, including drag cars, where parts live and die at the limit of their material. That background changes how you design printed parts.
A mechanic doesn't ask what a part looks like; they ask where it fails. Which face takes the load, where the vibration concentrates, what happens when it heats up, which fastener backs out first. Those instincts transfer directly to fabrication: print orientation becomes grain direction, perimeter count becomes wall thickness, infill becomes webbing.
It's also why we'll tell you when printing is the wrong answer. Some parts want to be metal. Knowing the difference is the skill you're actually paying for.