I'm not on your list but regardless; I've been at this since before there were lawn chemical to treat weeds. I remember the ddt days and on and on. So to answer your question--To quit learning is to die. If your not growing; you are dying. Learning leads to discovery and discovery leads to questions and searching for answer. Being highly educated and an ex teacher with a very early degree in ag, I can honestly saw that our best days are ahead--one never quits learning. Reading and observation is the key.
We all are merely gleaners from the masters who were here before us.