Sehwag was undefeated on 99 at the lunch interval on Saturday, after going on the rampage during the morning period.
"I was upset because I knew that nobody from India has ever done it," Sehwag told reporters. "I was looking forward to that moment, but unfortunately I missed it. After lunch, I decided that having missed it, I would get my hundred, and play for my team, and bat until tea."
Sehwag was eventually dismissed for 180 - his 12th Test hundred, and said he enjoyed batting on the BCG pitch.
"It is a good pitch on which to bat and I decided that since there was nothing there for the bowlers, I would play my shots from early and just carry on," he said.
Sehwag, who has gradually regained the form that has been patchy over the last few months, said India would aim for a huge first innings total to bat West Indies out of the match.
"We would do better to bat only once on this pitch," he said. "It is going to get more difficult for batting as it goes on."
Sehwag also gave praise to West Indies left-arm bowler Pedro Collins, who collected four wickets to take his tally in Tests to 100. "He bowled in good areas and he was their best bowler, so he deserved the wickets he got," he said.