The impressions that space and the ambient environment can give have quite a profound effect on one's own basic mood and perception, which can then in turn powerfully shape the thoughts and experiences which occur on that base.
Going through a pass on a cloudy day for example can really serve to direct one's thoughts on the immediate surroundings, and give one the feeling of being enclosed and introspective, whereas a clear day can reveal the full spread of the landscape, and direct one's attention out and give rise to wide open and spacious thoughts.
