By profession, I was a scientist before retiring. I've always wanted to write fiction, and now I'm doing that. Professionally, I've done LOTS of scientific writing. The writing style and purpose there is VERY different.
In science, while you've no intention of boring people, the PURPOSE of what you're writing is to document scientific understanding. It is NOT to entertain. Therefore, the top priority in scientific writing is clarity.
We DO NOT use colorful words to entertain. We use CLEAR words to be unambiguous. And we DO NOT use different words to mean the same thing. If a reader sees a different word, he/she will assume that the reason that you've used a different word is because you mean something different.
In fiction, part of the fun in any story is the language. Not only can you use colorful words to try to get a laugh from the reader, or to spark the reader's imagination, but the characters in your stories might have different ways of saying things that are particular to them - just like most of the people that we know in real life.
Writing is expression.
