Spoiler: No, no you can’t. Unless you’re a Dementor. You aren’t a Dementor, are you?
The first Harry Potter novel was published in 1998, the same year the Battle of Hogwarts took place. Hence:
In Greek mythology, the seer Cassandra was cursed so that none would believe her prophecies. Professor Trelawney's great-grandmother's name was Cassandra.
The Mirror of Erised* shows a person's deepest wish. When Dumbledore looked he saw the same thing Harry did; his family happy and reunited.
*Erised is Desire backwards.
Ron Weasley's Patronus is a Jack Russell terrier, which have been known to chase otters.