You’re right, Nick. It is a word, but it’s considered “nonstandard.”

Irregardless is a word, despite the autocorrect database not including it: https://www.dictionary.com/compare-words/irregardless-vs-regardless?root=irregardless

The word “feel” has two definitions: 1.
be aware of (a person or object) through touching or being touched. 2.
experience (an emotion or sensation).

The word “think” also has two definitions: 1.
have a particular opinion, belief, or idea about someone or something. 2.
direct one’s mind toward someone or something; use one’s mind actively to form connected ideas.

Notice that these two words have two different definitions. That means that the words “think” and “feel” are clearly not the same words. Therefore, you should never use the word “feel” as another word for “think.”

Naked “This”

The word “this” should be accompanied by a noun or a verb. Consider this example: “This shows that he did not study for the test.” is not going to score any points with the reader. They are going to say “this what?” Rather, say “This failing grade shows that he did not study for the test.” It shows clarity and precision to the reader. You can say “This… is… Jeopardy!” and it will continue to be clear and concise to the reader.

Passive Voice

You never want to say “The game-winning home run was hit by Lou Gehrig.” Say “Lou Gehrig hit the game-winning home run.” Have some activity with your writing.