"Optimal" depends on how deep down the rabbit hole you want to go. "Slept well and wake refreshed" might be one version of it, but "slept like an infant in the

"Optimal" depends on how deep down the rabbit hole you want to go. "Slept well and wake refreshed" might be one version of it, but "slept like an infant in the womb and awoke younger and healthier" would be more optimal, if currently in the realm of science fiction.