The regular Mendix way is indeed storing the object in the db and retrieving it the next time. If you do not want to do that, for instance because you want to limit your dependency of the presence of the database, you will need your clientside to remember your object. This is probably possible by storing it in a cookie or a client’s local storage. Something that I have done by exception ages ago in php-web-applications, but never gotten around to trying this in Mendix.
You can create an association between the current user and a non persistent object. In that way, you can retrieve this object from memory everytime you need it, in the same session.
Do this by
Created persisted objects on the page can be associated to the non persistant helper object and commited on the final page, if you are trying to build a wizard or something like that.
GL!