expression
an old man is twice a child
Proverb meaning that elderly people can become childlike in behavior or need care similar to that of a young child.
祖父は最近わがままになってきたが、六十の三つ子というから仕方ない。
My grandfather has become selfish lately, but as the saying goes, an old man is twice a child, so it can't be helped.
The exact origin is uncertain; the expression literally means 'a sixty-year-old triplet,' humorously comparing an elderly person to a baby.