My mentor retired last month after forty years in the oil industry and told me I should get out while I am young and I cannot tell if he was giving me advice or confessing regret.
More people experience this than they realize.
Your retiring mentor told you to get out of this career, and you can't tell if it was advice or regret.
“Where Are You with Manufacturing — Oil, Gas & Energy Operations?”
If this sounds familiar, the Library can help you find the bigger picture.