Welcome to another Rishi DBD. As per recent trends, I'm attempting not to make this too much about myself. We'll see if that succeeds.
Also, I'm really not sure I have 150 words to complete this. Honestly, the DBD title says it all. Skills that everyone (or every man, or every woman) should learn. I guess I can list some out. Mine may have a slight bias towards skills that a man should have (also, they're all relative to modern society. Almost none of these will help if my plane crashes on a deserted island in the middle of the pacific ocean that also has a mysterious smoke monster)
1) Basic cooking - pasta, sauteed/stir fried veggies, etc
2) How to properly perform the essential weightlifts - deadlifts, squats, bench, pull-ups, presses, etc
3) Shaving with a safety razor or a disposable razor - I'm saying this as someone who only learned with an electric for the longest time (and I still haven't shaved with a safety razor yet)
4) Properly polishing shoes - With a brush/rag, water, polish, etc;
5) Removing a stain - Be it on the carpet or on your shirt or whatever, drinks or food or red wine will spill and it's good to know how to fix it immediately (hint, white shirt? apply some club soda and have a paper towel or a rag at the other end to soak up the stain)
6) How to tie a tie - self-explanatory. Come on, you're not 15 anymore.
This is by no means an exhaustive list. GO BEARS!