This is the 6074th most frequent Polish word.
alicję
"Alicję" is the accusative form of "Alicja," a Polish female given name equivalent to "Alice" in English.
Alicję here is the accusative form of Alicja, used because it is the direct object of the verb 'zaprosiłem' (I invited).
Zaprosiłem Alicję na kawę.
I invited Alicja for coffee.
Alicję in this sentence is again the accusative form, serving as the direct object of 'pamiętam' (I remember).
Pamiętam Alicję z dzieciństwa.
I remember Alicja from childhood.
In this context, 'o Alicję' uses the locative case after the preposition 'o', commonly used when speaking 'about someone.'