The Wallabies could have won the opening fixture at the death to leave the Leicester hooker and his colleagues in no doubt that more of the same might not be enough at the Etihad Stadium.
"We left some opportunities out there and that's something we need to address. We didn't play all that well but we dug out a win," said Youngs, who is convinced that the Lions will be all the better for their experiences when they return to the Test scene in five days' time.
"We were a bit naïve at times and we didn't adapt well enough to how the referee was handling the game. That's something we'll obviously need to work on. I don't really know what was happening with the referee. They all handle these matches different and we'll need to review the tape again.
"We didn't attack as well as we would have liked but that's a great thing to know. We didn't play to our full potential on Saturday night but we still managed to win the game.
"We all understand and realise there's still much more to come from this side. That gives us such a boost heading into the second Test. Believe me, we have learned so much from Saturday night. It was an incredible experience but we all know we can take our game to another level."
Youngs admitted he could have done without such a nerve-wracking finish to the first game of the three and he isn't expecting an easier ride next time around.
The Qantas Wallabies may have suffered some potentially serious injury setbacks at the Suncorp Stadium but the manner in which they hit back in Brisbane is a timely reminder of what lies ahead in less than a week.
"I couldn't really look," added Youngs in reference to Kurtley Beale's failed last-gasp shot at goal. "I was just thinking, 'miss, miss'. It would have been a massive blow to lose it at the end.
"I was sat next to Adam Jones on the bench and I just heard him shout, 'he's slipped, he's slipped. As it is, we go into the second Test with momentum behind us.
"It was a remarkable night but my heart was in my mouth at the end. I think we all felt the same way. But at the end of the day we won the game and that's all the matters.
"Australia are a very good side and they showed what they can do. Regardless of who is injured Saturday is going to be another tough match. We just need to ensure we play much better."