My dad "isn't a rocket scientist", as we'd say in Chicago, but he knew a few things. His wisdom came to us through choice sayings, always a bit dour (in the characteristic Lutheran way):

• Parking lots are complete chaos. Chaotic environments are dangerous. It would be hilarity to see an autonomous vehicle try to navigate the sea of lane-line crossings, angle-in parkers, backward drivers, strollers, pedestrians lurching into the street, and tons of small kids, in front of any big box store.
• Moisture is the enemy of the home. Water causes many (most?) household problems: mold, rot, foundation damage, etc. Never ignore water. Larger lesson: be responsible and don't ignore taking care of things. You'll save a lot of money and time fixing small problems before they become large, and urgent.
• Call them first. Time is precious; optimize. Be smart. Don't do today what you could do in half the time tomorrow (via batching or going somewhere closer to home). Avoid making special trips. Don't go to stores that aren't open or don't have what you need. Unforced wastes of time are the plage; avoid them at all costs (to this day, they're a major peeve of mine).
• Discretion is the better part of valor. Sometimes it's OK to walk away from a fight. Don't start big projects when you're tired or try to lift too much by yourself; you'll just end up hurting yourself, or doing sloppy work you'll have to redo.
• It's always something. Murphy's Law says "anything that can go wrong, will"; there are a lot of things, so expect something is always going wrong. Human vices—forgetfulness, carelessness, sloppyness—always get in the way of things. Be tough; deal with it, keep going, and above all, remain cheerful.
• Dollar bills flying out the door/window. Said when a door/window was left open during the winter, letting the heat get out; a reminder that big wastes of money are often small, ongoing things (e.g. credit card interest, water leaks), and to avoid that cardinal Midwestern sin: wasting money.

My dad embodies what Stripe (the payments company) calls "micro pessimism but macro optimism": everything is always broken, messed up, and wrong, but in the end, things will be better than you can possibly imagine.

I love that.