I try and walk every day for up to an hour. I started years ago as a single parent and petrol had to be on a budget. I also hate waiting for a bus when it's cold and wet, I'd rather keep moving and keep warm that way. Often getting to a destination before the bus does!
When walking I often think through projects, think a problem through, stomp off a bad mood, think of all the things I'm grateful for etc. so find it good to keep things in perspective and balance.
It's good for bone density, core strength, posture, digestion, good mental health and appreciation of life/nature etc. I don't know about losing weight, just know that a few people I know who are overweight do not walk or exercise and never have. I've been the same weight and size for 40 years though, and believe me I really love my food!