Why are children so bored during the half term holidays?

How hard is it to plan a whole week of activities for your children to keep them entertained and not hear the dreaded words “I’m bored, what can I do?”

I tend to do all of the below:

Trips to the Park

Painting

Baking

Lots of outdoor play

Trips to library

Trips to the Museum

If I fit all these trips and activities with a little careful planning I can usually get through the week without them getting too bored.  With all the outdoor play they usually get quite tired and easier to please.