Intrinsic motivation is the inspiration from within. With this kind of motivation a person work independently pushing his goal to achieve. According to Oudeyer (2007) citing the work of Ryan and Deci (2000), intrinsic motivation refers to engaging in an activity for its own inherent satisfaction — not for any external reward or consequence. In other words, a person is motivated to do something because the activity itself is enjoyable, interesting, or challenging, rather than to gain prizes, grades, money, or approval from others.

The same point of view from Neuhaus (2021), intrinsic motivation refers to the internal drive to engage in an activity for the pleasure, interest, or satisfaction the activity itself provides, rather than for any external rewards or outcomes. It arises when a person does something simply because they enjoy it or find it meaningful, not because of grades, money, or praise. So the person initiated the tasks.

Here are examples of activities that are typically intrinsically motivating:

Reading a book for enjoyment because you love the story or topic. Like when I was in high school. I love reading love story, even the time is midnight already I still wanted to read because im interesting to the story.
Solving puzzles just for the fun of it, not for a prize. It’s feel satisfying to a person when he can complete his answer on word puzzle. It’s quite pleasure to other people but for some people they found it punishment when they are required to answer it.
Painting, drawing, or playing music because creating art is personally rewarding. People who are artistically inclined they enjoy doing their habit during their vacant time
Studying a subject because you are genuinely curious, not just to get a high grade. Learning interesting topics sometimes encountered by the students. They ask questions to understand further the lesson not to achieve better grade but still part of the equation.

These activities are done for their own sake and bring satisfaction simply through engagement.

Neuhaus, M. (2021, May 10). Intrinsic motivation explained: 10 examples & key factors. PositivePsychology.com. https://positivepsychology.com/intrinsic-motivation-examples/

Oudeyer, P. Y. (2007). What is Intrinsic Motivation? A Typology of Computational Approaches. Frontiers in Psychology. https://pmc.ncbi.nlm.nih.gov/articles/PMC2533589/