Dream of swim, screaming, boat

I dreamt that i got off the buss at a buss stop. then i remebered i forgot my wallet on the buss. The bus was now on the farry going over the ocea. i ran on it and talked to the man in charge telling him i forgot my wallet. the boat started going and i was on it. the man couldt give me the wallet yet for some reason. suddently i was in the big dark blue ocean. i tried to keep my head above whater but i kept sinking. when i tried to swim i would just go further down. the man on the boat was looking at my and screaming for me. i stayed calm with no real worries. suddently again i was home. then the man from the boat came to my house with my wallet, he also gave me a pizza and something else. my sister asked why and i said it was because i almost drowned like i didnt care and like it was nothing, and like i was irritated at her for worrying and freaking out. im like whatever forget it, its no big deal. what can this mean?