Well, 2 things . . . first one can hike for 20+ years about 2-3 times a year and about 5 or so miles per hike totalling less than 400 miles in 20 years or someone could get out on the trails every weekend for 10-20 miles a weekend for 5 years for a count of about 2500 - 5000 miles in 5 years . . .
Don't know if years has anything to do with it.
And secondly, I sure hope NOONE EVER uses words like "grizzled" to describe me ever even after 20+ years of hiking
I have been hiking for about 12 years now . . . I used to hike about 3-5 times a year and probably hike a total of 25-35 miles per year UNTIL about 6 years ago. 6 years ago at a "turning point" in my life during a very difficult time I found myself feeling all alone, almost abandoned by everybody and tackling a difficult transition in my life and that is when I turned to the outdoors for solace and strength.
My hiking days per year as well as the miles per hike have steadily increased each year for the past 6 years. In a "normal" year now, I hike about 600-800 miles . . . BUT last year, my not so normal year of fun, I hiked about 1200-1400 miles (haven't counted them all up but I know it is right around that)
And even after all this hiking if someone were to ask me to "rate" my hiking experience and skill, I would still say I am an "intermediate" or "very advanced beginner" level hiker . . . don't know if any amount of time or experience will change my preception of myself all that quickly.
But in relation to this topic, I would wonder why anyone would want to classify themselves when it comes to hiking. I find that I get enough "categorizing" in my "daily real world" life.