Bookmark not working as Bookmark

Hello Adobe Programmers? I am using Adobe Reader DC free version but it seems the bookmark option isnt working as a bookmark. May you please add the functionality for allowing me to mark a page where i finished off reading so that the next time i open the same document i get back to where i was working from. Its kind of boring having to type page number or scroll looking for that previous section. If there is a way to do it, Please just send the instruction on this post or my email address. Thank you.