That's because you have:
Set in the configuration (near the top of the script). Use off instead of on, if you prefer they always be closed. Using on remembers their state and returns it onload. And since you seem concerned to have things as closed up as possible, consider setting the green no to yes. This will collapse any open items when a new item is opened.
var enablepersist="on" //Enable saving state of content structure using session cookies? (on/off)
var collapseprevious="no" //Collapse previously open content when opening present? (yes/no)