Since a person sleeping is in a suggestible state and unable to make judgements, they become easily deceived by what appears in their dreams, like the infatuated person.
sˈɪns ɐ pˈɜːsən slˈiːpɪŋ ɪz ɪn ɐ sədʒˈɛstᵻbəl stˈeɪt ænd ʌnˈeɪbəl tə mˌeɪk dʒˈʌdʒmənts, ðeɪ bɪkˌʌm ˈiːzili dᵻsˈiːvd baɪ wʌt ɐpˈɪɹz ɪn ðɛɹ dɹˈiːmz, lˈaɪk ðɪ ɪnfˈætʃuːˌeɪɾᵻd pˈɜːsən.