it hit me

The Pursuit of Happynessの主人公の母は、恐らくDVを振舞う夫を殺そうとした罪で、刑務所に入っている様ですが、主人公が大好きだった叔父の葬式に母は参列することを許され、久し振りに母の顔を見かけます。
Every time I looked over at her, hoping for some sign that she had seen me, all I saw was the pain of losing her baby brother and not being able to talk to her children. She kept her gaze down at the earth where they put Uncle Henry's casket.
When it hit me that the woman standing next to my mother was a female prison guard--the only white person at the funeral, dressed in a navy-colored uniform--it came down like a thunderbolt where she had gone.
"it hit me" は会話のテキストに出てきそうな表現です。この手の表現を辞書で調べるのは結構苦労します。案の定 "it hit me" での検索でヒットしたのは次の辞書だけでした。
・Urban Dictionary: At that moment, I finally understood.: After my fish died, it hit me: I had taken his ever-presence for granted.
しかし、たいていの辞書にもこの意味は "hit" の説明にありました。
・Macmillan Dictionary: if an idea or the truth hits you, you suddenly realize it: It suddenly hit her that she would never see him again.
・Collins Dictionary: to become suddenly apparent to (a person)   ⇒ the reason for his behaviour hit me and made the whole episode clear