About mountains: when I was aged less than 10, as a family we all climbed The Old Man Of Coniston. The view from the top was still familiar the next time I saw it, decades later. Some five years later, the next notable climbing experience was in the Pyrenees when we camped in Andorra. Nothing much happened after that for fifteen years or so, when the experiences described in the MEWILA book began.
About science: again, before the age of 10, my father taught me how to build a radio. Later, he showed me books on cosmology. My student summer jobs included two with zoologists, one with computing people, and one with weather forecasters. That is not obviously why I studied mathematics.
About human character: some background in this subject can be very useful, if one wants to survive long enough in employment to collect a pension.
About riding bicycles: it is a good experience, and a good way to travel.