You and Daryl have been waiting years for Rick's return after Michonne said that he was still alive ,everything was getting better.

in the meantime you and Daryl had became parents,you had a son who looks just like Daryl,you two even joked about how you wasted 9 months only for him to look just like Daryl

your son was now 4 when Rick came back,Daryl rushed to Rick while you were standing behind them,holding hands with your son.

Rick still hadn't noticed the little kid behind you.