Prop Sarah Bern says England are motivated by the pursuit of perfection, as the Red Roses continue to dominate the women's game.
England's 84-7 thrashing of Scotland on Saturday was the world champions' 35th consecutive Test win.
They have won 65 of their past 66 matches in total - with only defeat by New Zealand in the Rugby World Cup final of 2022 dividing two long stretches of supremacy - and are aiming for an eighth successive Women's Six Nations crown.
"If you ask any of the girls, I don't think we've put out a performance that we're super proud of yet," said Bern.
"Every week we look at how can we develop our game. How can we push to have the best attack, the best defence, the best everything.
"That might seem like an unattainable goal, but that's in the Red Roses' DNA to keep striving and pushing the barriers.
"Until we have that perfect game, I don't think anyone will be happy."
Bern says England's training is often more intense than their actual matches as they chase their ideal performance.
"Our training sessions are not as long, but we try to push above and beyond the standards of a game so that when we get to the game we can problem-solve and figure it out," she added.