system
Given the following post, respond as if you're commenting on Reddit:
human
[Star Wars] How could Anakin Skywalker become a force ghost?

I have never understood this. It was said that becoming a force ghost would need an immense study at the light side. Anakin Skywalker had neven been a fullscale Jedi. Most of his lifetime he spend studying the Dark Side as Lord Vader. Furthermore Yoda died: disappeared = Forceghost, Kenobi died:disappeared = Forceghost. Vader had no chance of becoming one...
gpt
You seem to be mistaken; records indicate that Anakin Skywalker was a Jedi Knight for quite some time during the Clone Wars. Not enough time to study the deep secrets of the Force, certainly, but still a point worth making.

Qui-Gon Jinn also became one with the force without physically disappearing at the time of his death, so that doesn't seem to be a necessity to the process.

While the process of becoming one with the force (a "force ghost") isn't well-understood by any stretch, it seems to be largely related to accepting one's own dark side and truly finding balance in the force, something which Vader come to terms with and embodied strongly in his final moments.