It is good even for old men to learn wisdom.

Age is not what ends the learning, and believing that it is does most of its damage from the inside. People decide they are too far along to start, and that decision quietly closes doors which were still open. Long experience makes you better at many things and worse at one: noticing that you might be wrong.

A fair test is whether you have changed your mind about anything substantial in the past few years. If not, that is not necessarily stubbornness, but it is worth investigating. Take up one thing you are visibly bad at and stay bad at it in public for a while.