The 33-year-old, who is most likely playing his last World Cup this year, said he loves spending time with youngsters in the camp, especially KL Rahul and Hardik Pandya.
"Those two names matter a lot to me. I am very close to them in this Indian team. If either of them was not there in the team I would have been very sad. At the end of the day, you do make close friends as you go along in the journey," Karthik told PTI before leaving for England.
"I would not still be playing if it was not for the blessings of my friends and family. Good or bad, if people still talk about you it means that you have managed to stay relevant. It is extremely satisfying that I have managed to stay relevant all these years and still trying hard to be part of the team."
Karthik has experienced the highs and lows, whether it was being part of India's disastrous run in the 2007 World Cup or the World T20 triumph in South Africa months later. Karthik, who was then in his early 20s, vividly remembers those contrasting campaigns.
"We played two World Cups in 2007. We were very successful in the T20 format and one World Cup where things did not go as per plan. Leading up to it (ODI World Cup), we were playing some really good cricket. The format was such that we got to play three games and we had one bad game against Bangladesh and that really hurt us.
"After that game it was like playing a three-match bilateral series. You had to win the next two matches and there was so much pressure. That is the thing about World Cup.
"But the T2O that followed was a breath of fresh air. The format was new. With Dhoni leading the side so well, it was a great tournament to be part of."