I'm driving down the street and I see a group of young people, who look like tourists judging by the bags/blankets/pillows they are schlepping, try to shuffle faster through the pouring rain. It isn't uncommon to see people who look like they are carrying nearly everything they own as they walk down the streets of Las Vegas, but doing this in the rain is definitely an uncommon thing in this city as it usually rains about four or five days per year. It's been a soggy few days here.
So I began to wonder why these people would let everything they have with them become a soggy mess and it dawned on me that they must have missed life lesson #234--learn how to improvise.
If you unexpectedly find yourself caught in the rain, in a big city, and DON'T want all of your worldly possessions to become a wet mess, find the nearest pubic garbage can (sometimes on city streets, other times in public restrooms, hotels, etc) and pull out a trash bag (look under the bag that is in the garbage can as many janitorial folks will leave additional bags under the bag they are lining the can with) and...instant pack/suitcase/blanket rain cover. You can also improvise a rain coat this way by tearing holes in the bag for your head and arms.
Need a water bottle? You can find these discarded everywhere, just go to a public restroom and wash them with soap and water before filling it up. Doing the vagabond thing and want to heat up a meal only you have no stove? It's simple to scavenge the materials to make one.
Where ever you find yourself, take a couple of minutes to look around and notice everything in your area. With the things you see, what can you improvise with them? Weapons can be commonly improvised from everything from a stick to a rock. I've lost count of how many times I've seen homeless guys pick up a cup from outside a fast food restaurant, go in, and fill the cup up with their beverage of choice (highly unsanitary, of course, but it seems to work for them).
Learn to improvise things--whether you actually need these things or not--as yet another survival skill that may come in useful in the future.