What is an idea?

I’m on day 2. When it asks for the idea that lead me to graduate college I wrote that I wanted a degree.
writing a book = it will give me social proof
public speaker = help others overcome their limitations
visit 16 countries = I want to be cultured.

I bought my first new car when my old car broke down. So what was the idea there? I want a reliable, new tech-savvy car?

Are these ideas or reasons? I am finding it difficult to know the difference and it’s important I understand this.

Thank you