its possible in general it depends on the person just like for example one person can do their homework while watching tv but others need one or the other not both
personally i have so many stories i'm working on but i can still get them all done eventually it all depends on what kind of mania i get on a story.
as long as the different stories have strong enough themes that will be easy to remember. But don't write similar stories at the same time or as I said before you might forget what each was going to be about