Johnny said: “do arahants dream since their minds are always mindful and bright..:
I have no idea whether Arahants dream or not. And it does not matter much anyway. When dreaming, one never generates javana citta (i.e., conscious thinking is not involved). In Abhidhamma language, those citta vithi involved are parittarammana and atiparittarammana citta vithi which do not have javana citta.
– So, dreaming is a “passive state”: one just experiences what is shown in the dream. For example, in bad dream one may see an animal chasing to kill oneself, but one is even unable to run or try to hide.
– However, as one’s gets purified, one will stop seeing such “bad dreams”. That I know by experience. However, whether all dreams stop for an Arahant, I don’t know.
Y not said: “..dreaming in the waking state, fantasizing..”
Fantasizing is not dreaming. This is VERY important to understand. One must stop fantasizing as soon as one becomes aware of it; that is part of Satipatthana.
– When one fantasizes one is consciously thinking about a previous sensual experience or an anticipated future sensual experience. These are part of vaci sankhara that lead to “bad vinnana“, i.e., they are done with javana citta: “Correct Meaning of Vacī Sankhāra“.