The striker has finished the season helping La Dea win the Europa League and qualify for the Champions League. But he was also called "lazy" by Italy coach Luciano Spalletti.
"I don't know. Honestly, I would not have reached this level at Atalanta if I were lazy," Scamacca told Sky Italia.
"This is the coach's view and perhaps he is right, but I don't feel lazy. I am the first to enter and the last to leave (Atalanta training centre) Zingonia, but if he says so, it means I'll arrive even earlier.
"I knew I could do well here, but it took time to settle in and understand the coach and tactics.
"With a little bit of patience, we got some satisfaction.
"When you reach such self-esteem, it's like a drug.
"You want more and more, and you want to improve. After that night (at Anfield), we became aware of our qualities and found the energy for a great end to the season."