Because the Nation Israel had to leave Egypt in such a hurry they did not hav etime to allow their dough to rise. Therefore, they had to prpeare unleavened bread to take with them. In remembrance of their freedom (escape from Egypt) the Lord instituted a feats of the unleavened bread.
In the process of eating the unleavened bread for seven days the head of the household would be required to teach their children why they did this. verse 8 says “…‘This is done because of what the LORD did for me when I came up from Egypt.’”
In like manner I believe we should teach our children and grandchildren why we celebrate certain special days such as Christmas and Easter. Why we go to church every Sunday and why we do this or that for the Lord. If we do not tell them they will get their information from some one else and there is no telling if it will be correct or not.