Ireland's talismanic fly half is clearly seeking to draw inspiration from Martin Johnson's great England team and with good reason as the two sides headed into the respective World Cups in unerringly similar form as the game's top-ranked side.
England's 2003 Grand Slam winners went to the World Cup on a run of 31 wins in 34 games that included multiple victories over New Zealand, South Africa and holders Australia and, most notably, back-to-back defeats of all three the previous November.
Ireland extended their current streak to 22 wins in 24 games with Saturday's defeat of England, a run that has also been littered with victories over the best of the northern and southern hemisphere, and a first series loss inflicted by any team on the All Blacks in New Zealand in 27 years.
"When England won in 2003, they had a Grand Slam in the same year so we need to keep our feet on the ground and we need to keep building," Sexton, who plans to retire after the tournament in France, told a news conference on Saturday.
The Six Nations record points scorer also mentioned the 2003 Grand Slam earlier in the week, saying it showed how England could perform on the big occasion in a World Cup year.
Sexton witnessed it first hand too as a teenage fan that year when England hammered Ireland 42-6 in a winner-takes-all Six Nations decider at the old Lansdowne Road stadium.
There are similarities between the two sides - a dominant pack and a match winner at 10 - while in the likes of Dan Sheehan (24), Tadhg Furlong (30) and Caelan Doris (24), Ireland possess the kind of explosive players needed all over the park in the modern game.
They also share a ruthlessness in winning games well and conceding few tries. Ireland were far from their best on Saturday, but their performance in the 32-19 win over 2022 Grand Slam winners France earlier in the tournament was among the best seen in Dublin since Johnson's men came to town.
Ireland will face England again in one of two warm-up games in August before travelling to France where the perennial World Cup under achievers could not have asked for a tougher draw.
They face pool games against holders South Africa and a resurgent Scotland, before a quarter-final against world number two France or number three New Zealand. Ireland could for once be at their best and still face yet another quarter-final exit.
Or this time it could actually be different.
"There are bigger fish to fry than this," coach Andy Farrell said after Saturday's victory. "We're a good side that's nowhere near reached its potential."
