Answer:
It can be very helpful - if the older person is actually wise and sincerely wants to help you. One of the positive things about aging is accumulated wisdom, and many older people really want share what they know and be helpful. I’ve learned a lot from older people throughout my life. I really like to “pay it forward” if I can (e.g. Quora)
People learn the most from their mistakes - what better way to learn than from the mistakes of others where you can avoid the negative consequences.
Older people are not always wise, so you need to apply critical judgment. A thoughtful and truly wise older person will be able to explain the basis of what they are telling you…such as mistakes they made in learning or things they tried that didn’t work. This is a great way to evaluate their wisdom.
You also need to be receptive. It’s all too easy to hear genuinely good advice as “another story”. Listen thoughtfully and you may find some pearls.
And if you do learn something useful, provide feedback to the mentor…it will encourage them to help you in the future.