Walking and benefits to creativity

Taking walks is a way to solve problems. I find when I go for walks with friends, families and co-workers I always end up talking about something that presents a problem or challenge and by the end of the walk solutions seem to arrive as if by magic. Why is that? Anyone? I will think about this some more on walks to come and will be back with more information. Hopefully it will be more grounded with additional thoughts and perspectives other than my own.