The two teams will meet at Cardiff’s Principality Stadium on Sunday with Italy and France and England and Scotland having clashed the previous day.
Wales were beaten twice in Dublin in 2020, but the last time Ireland came to Cardiff for the Six Nations the home side came out 25-7 winners to seal a Grand Slam.
“It only feels like yesterday since we were finishing up the Autumn Nations Cup and a disappointing end to the Six Nations, the last campaign for us,” Sexton said.
“All Wales teams, they’re very tough to play against at all times, but especially in Cardiff.
“It’s a tough place to go. There are not many teams that go there and get a win.
“We haven’t done it in a long time.”
Ireland will be without injured forwards Caelan Doris and Quinn Roux for their game with Wales.
Sexton and his team were right in the frame for last year’s title only to lose out on the last weekend.
“We haven’t honestly spoken a day past Sunday or thought a day past Sunday. Since we met up last Wednesday, everything has been geared towards this game,” said Sexton.
“We know how important it is to build a bit of momentum in this tournament.
“The way we can start that is by putting out a good performance first and foremost. Hopefully the result will take care of itself if we can play really, really well.
“We’re going to have to if we want to beat a Welsh team away from home.”