Is it possible to mark questions as personal bookmarks on my profile page?
A list of my own questions is displayed but I wonder how I can add other interesting questions I would like to remember!?
As stated in my comment(s), marking a question as a favorite, by clicking the star below the arrows for up- or downvoting is a solution. Later these can be listed by the user. This a good system to show at the same time that the question (or an answer to it) was particularly valuable for a user.