I would argue that Bottom is changed by his experience in the forest. It may not be overtly evident: Nick Bottom will never be considered the best actor, or the smartest of Shakespeare's characters, but he certainly recognizes that something unexplainable has happened to him, & he wants to preserve its memory. When we first meet Bottom, he is eager to demonstrate his acting talents. He is assigned the role of Pyramus, and he volunteers also to play the role of Thisby and that of the lion. Quince convinces him, however, that he "can play no part but Pyramus."
At the first rehearsal, Puck changes Bottom's head into the head of an donkey. When the rest of the machanicals see this, they run off, frightened. Bottom thinks they are playing a trick on him, trying to scare him, but he meets Titania, who has just woken up, having been anointed with the love juice by Oberon. Titania swears she is in love with Bottom, and he replies ''Methinks, mistress, you should have little reason for that". When Titania tells Bottom that he is both wise and beautiful, he assures her that he is not. Nevertheless, he seems to accept her affection and follows her with little objection. When Bottom and Titania fall asleep, Oberon reverses the effect of the love juice on Titania. As Titania wakes up, she sees Bottom lying next to her and exclaims "O, how mine eyes do loathe his visage now!". Puck then returns Bottom to his former self. When Bottom awakens, he determines that he has had a "rare vision", and he vows to get Quince to write it down for him.
Bottom is considered by many critics to be the central figure of the play, because he seems to represent the common experience of humanity. Additionally, Bottom is the only character in the play who can see and interact directly with the fairy world. When he wakes up and has been returned to his former self, he acknowledges that something has happened to him, and it would be foolish to try explain it: "I have had a most / rare vision. I have had a dream, past the wit of / man to say what dream it was. Man is but an ass, / if he go about to expound this dream". In fact, it is this speech, referred to as the awakening speech or soliloquy, that intrigues many critics. The speech is often argued to be indicative of Shakespeare's acknowledgment of the possibility of spiritual life beyond our everyday existence. The speech is also said to demonstrate both nature's and love's inexplicability. Additionally, Bottom's lively involvement in the thus, it is clear that he has been somehow changed by his adventure.