This is the 10704th most frequent Russian word.
воспоминаниями
"Memories."
The word 'воспоминаниями' is used in the instrumental case, meaning 'memories,' and depicts something he shared.
Он поделился с нами своими воспоминаниями о детстве.
He shared with us his memories of childhood.
Here, 'воспоминаниями' is used in the instrumental case, used to describe the action of immersing into memories.
Я люблю погружаться в свои воспоминаниями, когда чувствую себя одиноко.
I love immersing in my memories when I feel lonely.
In this sentence, 'воспоминаниями' functions in the instrumental case to indicate means or accompaniment, describing how memories are revived.