“If so, slow down and give yourself time to adapt physically and mentally. “
Don’t discount the learning curve of apparently simple things. Like hiking on a trail with a backpack on. Some of us have thousands of hours of experience at that starting as children on family or Scout trips. I can look at a stranger’s foot placement and height of each step and gauge pretty accurately how many years they’ve been hiking/backpacking. It took you YEARS, from age 1 to 5, of spending a few thousand hours a year to learn to walk reasonably on perfect flat surfaces with nothing on your back. Add an additional 15-30 pounds on your back and having to step over roots, rocks, deal with slick surfaces, puddles, uphills and downhills, and YEAH, there’s a learning curve to it.
There’s more than there appears to playing the piano, sex, hiking, or driving a car. Some aspects need to “over learned” through hundreds of hours of practice (finger placement, scales, balance, lane position, maintaining speed) so you can consciously focus on higher-level challenges.

