Going to school might sometimes seem a pain - but for millions of kids around the world it's not always possible to get an education.
The right to education is protected by international law and has been for decades.
But the United Nations estimates that around the world, over 100 million kids are missing out on an education.
Pakistan has the second-highest number of out-of-school children in the world.
Many children there don't go to school because they have to work to provide for their family.
For fifteen years, head teacher Muhammad Ayub has been running a school for disadvantaged kids in Islamabad, Pakistan's capital.
School starts at 5pm so the students can get there after they finish work and the classroom is the playground of a local park.
Some students are as young as five, others as old as 15. They're taught all the usual subjects like English, maths and science as well as Islamic studies and Urdu.
Mr Ayub says: "The truth is that these kids are poor and their parents must make them work; but it's my job to make sure that these kids get to study.
"These kids deserve to have a future and education is the key for that... I have helped thousands of children make it."