As soon as you said 1-8 that says it all. Most (though obviously not all) elementary schools do not go that high. There are what are known as junior high school or middle school.
I am guessing you went to a private school. Personally I think it is nuts to have 13-14 year olds in the same area as those who are 6-7
I went to Catholic schools in NYC. The local public school was k-6 and the junior high was 6-9 - but they were in the same building. The public high schools were 9-12 because they had to accommodate the kids from the 1-8 schools.
The district where I live in Virginia is a bit strange, most of the elementary schools are k-5, middles school is 6-8, and 9-12 for the high school - with 2 exceptions. There are 2 islands which have their own schools even though they are part of the same district. One island town is one school k-12, the other has 2 schools, k-5 and 6-12.