I like ya cut g *slaps head*
Answer:
The reason that Wilson thinks Gatsby killed Myrtle is because Tom told Wilson that Gatsby was the owner of the yellow car that had hit Myrtle. Wilson thinks that the reason as to why he killed her is because he didn't want to talk to her for the moment.
Explanation:
Learn from your mistakes and live for today don't dwell on what happened yesterday and hope for tomorrow is hope that tomorrow is better than today.