My friend was in merchant navy and he is new on ship and he is completed 1 month there and he told me intially in 10-15 days he got full sleep bcoz of tired after work..but from past 10 days he told me he had getting same dreams like he was stuck in his work place related to that and he just wake up in middle around 2-3 am and check whether he stuck in real or not then after few moment he realized that he is in dream..initially he check for his working clothes that he wore same cloth and sleep he checked weared clothes and place..I spoke to him any stress or anxiety he told me no..and he enjoy his meal and after work he was tired and nothing to thought anything..bcoz of tierdiness..and I asked his thoughts before sleep he told nothing after dinner within 1-2 hr he sleep..his sleep cycle is around 7-8 hrs and he talked to his friends and other members..daily basis.. So what could be the possible reason and solution..