Can I use this code in my personal project and discard the MIT License?
Sure. You can use the code however you want. US law permits ordinary use without significant restrictions. If you buy a book, you don't need a license to read it.
The problem is, if you wish to duplicate or distribute elements that you didn't author (or do anything else that US law requires you to have a license to do), the only thing granting you the right to do that is the MIT License. There's nothing you can do to change that other than to get a different license from the authors of those elements. You will have to comply with the MIT License with respect to those copyrightable elements in the project that you did not author.
The only thing that license requires of you is that you do this: "The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software."
Now you don't have to do that if you don't want to. But if you don't, you don't get the license. And then you would have no legal right to distribute, modify, or copy (other than as necessary for your ordinary use) the protectable elements in the project to which you do not personally hold copyright.
Note that this answer is based on US law. There are other countries where this reasoning does not apply.