Potions is the subject taught by Severus Snape one of the teachers Potter loathes throughout the series. He is quite partial to his own house the Slytherins and leaves no opportunity to taunt Harry and his fellow Griffindors.
There is a lot of variety in the potions these wizards and witches come across.
There is verisaterum which is kind of like a lie detector. It will force the person who had it to speak the truth and nothing but the truth.
There is a love potion that will cause a person to fall head over heels over another.
Then there is the polyjuice potion that contains the hair of another individual and helps one in impersonating . It plays a significant part throughout the series .
One person taking the form of another is a common aspect of kost mythological or folklore stories. In the Ramayana , Sita is abducted by Ravana disguised as a mendicant after using a demon disguised as a deer to lure Rama away from her.
There was an interesting interview I saw recently of South Indian movie actor Mammootty. Some reporter went to him and asked what he would do if he would wake up in the morning and find that he is ... ( specifying some other name that had been finding a lot of place in recent press articles) . He quipped "No matter who I am when I get up I will first go and have my cup of tea." Exactly , end of the day we all share some basic needs no matter who we are .None of us get more than 24 hours in a day ! None of us can be without food or sleep.
If you wanted to impersonate someone who would it be ?