Note: Please answer only without mentioning the sequel movies in the Harry Potter series. I've only watched the first movie. Watched all in my childhood but now I've to watch all again. If it's not possible without mentioning the sequel movies, you can skip it.
I was watching Harry Potter and the Sorcerer's Stone again (the last time I watched it in my childhood on TV and didn't have much understanding).
In the end, Voldemort's soul tries to enter Harry's body. I read some articles which say it happened because Voldemort wanted to stick himself to Harry's body as a parasite but failed and he came out of Harry from other end.
Now, immediately after that Harry got terrible pain and he became unconscious. So I don't exactly understand why it happened. Did some soul part get stuck inside Harry that hurt him?
Or would that stuck part hurt him later in life and give some "Voldemort Symptoms"?