I understand that powering the motor from the 5V pin deteriorates the arduino in time, not immediately
In fact the Arduino can be immediately destroyed. Wildbill was speaking figuratively.
I'd rather understand it all
Plan on taking at the very least a year each of college level introductory physics and electronics to even approach that stage. On the other hand, you can follow recommended tutorials (Instructables are NOT recommended) and have some fun, while getting a glimpse at a very complex, advanced area of technology.
Hint: if you are interested in motors, avoid any project that recommends L293 or L298-based motor drivers. They are dinosaurs and won't even work with many common motors.