England take on Australia in Brisbane from Thursday looking to respond strongly to their eight-wicket defeat inside two days in Perth, where Root was dismissed for zero in the first innings before falling for eight in the next.
"It's pretty disappointing in terms of the numbers," Root told reporters on Sunday.
"First innings, I thought it was a good ball. It's one of those things you can get early on. You've got to try and find a way to get through that phase when it's tricky at the start.
"And then second innings I thought my tempo was really good, made one mistake. You play a miss at that or it goes between the keeper and it slips for four, you never think of it again.
"I think it's having a bit of realism, understanding, yes there are things that I might have done differently if I get an opportunity again, but also it's not the end of the world."
Former England captain Root has now gone 29 innings without a century against Australia in test matches Down Under, sparking criticism of his form, but the 34-year-old had no doubt about his ability to score again.
"I'm making sure I'm clear on how I want to construct an innings against the pink ball in these conditions, against this attack," Root added.
"That's what this week's about ... just readying yourself as best as possible, having good conversations around things on how we can work together and build those big partnerships that are going to set up games for us."
Australia have won 13 of their 14 day-night tests with their only loss coming at the Gabba last year against West Indies, and Root questioned the need for a pink-ball Ashes test.
"It's very successful and very popular here," Root said.
"Australia has got a good record here. So you can see why we're playing one of those games. Ultimately, two years out it's going to be there. It's part and parcel of making sure you're ready for it.
"A series like this, does it need it? I don't think so. But it doesn't mean that it shouldn't be here either."
Media reports said on Saturday that Mark Wood was likely to miss the game with a sore knee, but Root said the England pacer would do everything to be fit again.
"We'll see how things unfold over the next little while ... every opportunity he gets to play for England, he puts his heart and soul into it to get well as fast as he can," he said.
"He'll be all about readying himself as best as possible."