I notice that a lot of beautiful literature contains sentences that are not grammatically correct. Here are some examples:
“Still, there are times I am bewildered by each mile I have traveled, each meal I have eaten, each person I have known, each room in which I have slept." [This lacks an "and" at the end of a list.]
“And so we beat on, boats against the current, borne back ceaselessly into the past.” ["We" is probably referring to people so there should be a "like" before boats.]
“There is a loneliness that can be rocked. Arms crossed, knees drawn up, holding, holding on, this motion, unlike a ship's, smooths and contains the rocker. It's an inside kind — wrapped tight like skin. Then there is the loneliness that roams. No rocking can hold it down. It is alive. On its own. A dry and spreading thing that makes the sound of one's own feet going seem to come from a far-off place.” [There are incomplete sentences.]
In the examples, if the authors had added the grammatically required words and commas, it probably wouldn't have sounded as beautiful. So, what is allowed in academic papers such as research papers and essays? For example, in high school essays, are you allowed to write incomplete sentences that make the sentences and words flow smoother?