As a college-level researcher, the projects, reports, and presentations you create will build on the work of those who came before you. Others who come after you may build upon your contributions.
Giving credit where credit is due is an essential part of this process. You've likely received dire warnings about what will happen to you if you don't give others the credit they are due or don't properly cite your sources in your projects.
While avoiding punishments and negative consequences is important to your future success, focusing on that aspect misses the real point of giving someone credit for their work:
Because it's fair. Because it's the right thing to do.
And because you want the credit for your accomplishments, don't you?
Take a walk in someone else's shoes with three stories of real people who did something amazing, and ask yourself:
Wouldn't you want the credit?