He feels that people have no more control over their lives than seeds blowing in the wind. If the wind doesn't blow, they can go nowhere, but when it does, they may be blown who-knows-where.
他覺得人生在世就像「風媒花」一樣的不能自主，風不來哪兒也去不了，真的起風了，卻又害怕不知將給吹到哪裡去。