Parents find themselves looking back over their own lives: the mirror doesn't reflect them as they are but as they were themselves as teenagers. Maybe for the first time they can now look back and ask:

'How was it with my adolescence? Have I fully come to terms with the issues that stirred in me then? Were there areas of fear and guilt which I suppressed, either because I felt I should or because others made me do so? And now that I face the adolescent stage in my son or daughter, is it these unresolved emotions that are rising up in me?'

The parent may project such emotions on to his teenager, and not accept them as belonging nearer home. But he will get further if he is able to take the mirror and see himself.

ไม่เข้าใจความหมายของประโยค not accept them as belonging nearer home ครับ,
มันหมายความว่ายังไงครับ, ขอบคุณครับ