You know, kids your age differ in lots of ways. Some are short and some are tall. Some are really fast and others are not so fast. Some can read really well and some have a harder time learning to read. There are just lots of ways that kids differ.
Kids can also differ in how energetic they are and in how their mind works.
Some kids don't seem to have very much energy - they just like to sit around. Other kids have so much energy, though, that it is very hard for them to sit still. Some kids are also able to really concentrate and think about one thing for a long time. For other kids, though, their mind sort-of jumps from one idea to the next. Having all these different ideas can be great, but when you have to focus on just one thing at a time, it can make things hard.