Australia captain Steve Smith said he took a sleeping tablet the night before his side won the second Ashes Test.
England began the final day in Adelaide on 176-4 in pursuit of 354, but were bowled out for 233 as Australia took a 2-0 lead in the five-match series.
“It has been a pretty tough 24 hours. I was a little bit nervous last night,” Smith said.
Australia will regain the Ashes if they win the third Test in Perth, which starts on 14 December.
Smith’s decision not to enforce the follow-on, despite Australia’s first-innings lead of 215, was criticised after they collapsed during the night session on day three.
The hosts were bowled out for 138, before Joe Root’s unbeaten 67 gave England a slim chance of pulling off a record fourth-innings chase.
“Would I do the same again? I’m not sure. It’s played on my mind a bit over the last couple of days – have I made a mistake?” Smith, 28, told BT Sport.
“On another day I might decide to go another way – but we’ve won the Test match, so it’s irrelevant.”
Australia bowling coach David Saker said on Tuesday that not enforcing the follow-on was “probably a mistake”, while fast bowler Mitchell Starc said the bowlers were not consulted in the decision.
“It’s a long summer and the bowlers we’ve got are very valuable,” Smith said.
“Just giving those guys rest makes me confident they can come back and do the business.
“It kept England bowling. They bowled 150 overs in the first innings. If you can tire their bowlers early on in a summer it can make a difference in the back end.”
Australia claimed the final six England wickets in the first session on the final day to complete a 120-run win in the inaugural day-night Ashes Test.
“We were very confident coming into today. We thought that we were still in the box seat,” Smith said.
“It all happened quickly. Josh Hazlewood turned things around with two breakthroughs early on.”
Australia have added all-rounder Mitchell Marsh to their squad for the third Test at the Waca in place of pace bowler Chadd Sayers.
Marsh – the younger brother of Shaun, who made an unbeaten 126 in Adelaide – averages 37.48 with the ball and 21.74 with the bat in 21 Tests.
He made 141 for Western Australia in a Sheffield Shield match at the Waca in November.
Australia squad for third Test: Steve Smith (capt), David Warner, Cameron Bancroft, Usman Khawaja, Peter Handscomb, Shaun Marsh, Tim Paine (wk), Mitchell Starc, Pat Cummins, Nathan Lyon, Josh Hazlewood, Jackson Bird, Mitchell Marsh.