Growing Together - Do milestones actually form who my sims are?

Perhaps it's designed that way, that infant milestones are meant to vanish? I mean, I know no RL person aged 20 who recalls when they had their first diaper failure, or first biting own toe etc. Or if they learned lifting their head before or after they learned laughing. These details i'm not afraid to see vanish later in a Sim's life, but if they affect a toddler's development (=talents) it gets a bit more interesting.