I've found that some individuals take a lot of time to gain experience, sometimes as a general rule and sometimes in specific skills. The general slow learners who are not fooling around but actually do their work are probably not too bright and I do not consider them as candidates for esteem elders. Those who take long time in specific skills, for example building although they are average or even good at farming, probably do not like the task or are uninterested in it.
I have a wonderful guy who likes work - he seldom takes any timeouts - but he is a slow learner unfortunately. Otherwise I might have had a very young esteemed elder in my tribe. It's a pity!
my first elder was like this it took three days to from adept to master her name was bora