When I turned 50 I decided that I should really learn to navigate so that I could enjoy the hills in a safer way. My dad and school had taught me to map read when I was a teenager but I knew I was rusty and that there was a bit more that I needed to know about the arcane pleasures of contours!
I started off by doing the Walking Group Leader (WGL) Award, now called Hill and Moorland Leader (HML) Award with a view to seeing how it went first before deciding if I wanted to take things further. I really enjoyed the training, consolidation and the assessment so that decided it for me.
I enrolled on the ML and it took me about 2 years to achieve it what with working full time and part time and not living very near to actual mountains, although the Pennines is a pretty good training ground.
My friend and I ran a small business teaching navigation skills under the NNAS registration for several years. I still do this occasionally now that I am retired from full time work.