'It's a Challenge to Bring Up Kids Because their Lives are Not Normal' - Roger Federer

New Delhi: Tennis legend Roger Federer says he wants to make sure that his children remember what "normal" is as their "lives are not normal".

Federer is married to Mirka, who was also a professional tennis player before retiring in 2002 because of a foot injury. The couple has four children -- two pairs of identical twin girls and also identical boys.

In the third part of CNN World Sport's exclusive "Roger Revealed" series, the Swiss professional tennis player opened up about how he met his wife and how they shared their first kiss.

He also spoke about what life is like as the father to two sets of twins, read a statement.

"I need to make sure that my children remember what normal is because their lives are not normal. It's a challenge bringing kids up but we're trying our absolute best," Federer said.

"... you take care of your kids first before you take care of your tennis.

"I didn't have children not to be part of the process. I stopped counting how many diapers I changed, how many times I read stories, how many times I put them to bed. I love children and the things they say: it's raw, it has no filter," he added.

On his wife, he said: "She's been there every step of the way. When I met her, I did not have a title yet. It would have been easy for her to say enough is enough now, I've seen enough tennis, I've played enough tennis myself.

"I think her injury that she sustained early in her career and had to retire unfortunately, I think her career may have continued in some shape and form in mine because she's a bit older, she had more experience."

Federer said he was barely 18 when he got to know Mirka at the Sydney Olympics back in 2000.

"(We had our) first kiss, we were both playing for Switzerland and we spent two weeks together in those dorms… we had the most incredible time and then on the last day before we all left, it was more than just a kiss I guess. It was something that led to something extraordinary for us, we are still very happy. I tried to tell her I was almost eighteen-and-a-half because she told me I was so young after she kissed me," added the now 37-year-old.