User blog comment:PastaMeCreepy/Waking Up/@comment-27007772-20150920150839/@comment-27007772-20150920175018

Your sentience starts at some point after birth. We do not know exactly when.

It is completely possible to remember small fragments and certain situations which left a massive impact on you, but you'll notice, you have more memories (even simplistic/useless ones) for each year you got older, until it fully kicked it. (The age everyone is referring to "waking up")