United Kingdom, Feb. 9 -- Seal thinks being a parent is the "hardest job" ever.

The 61-year-old singer has daughter Lou, 15, and sons Henry, 19, and Johan, 18 with his ex-wife Heidi Klum and admitted that now that his children are getting older, they can "understand the difficulties" of being a parent.

He told People: "They're not kids anymore. They're adults with opinions and views on life and different philosophies

"It's great because you start out raising kids, and then you end up, if you're lucky by the grace of God, with friends that you can confide in.

"And you get to respect their opinions and their views on life, even if you don't necessarily agree with them. And you learn.

"And as they get older, you see that they understand...