Depends on how you work, I suppose.
The website Writer In The Storm describes writing two novels at the same time as “juggling chainsaws”.
Go Teen Writers warns of running out of steam when writing, which could be why writers have multiple stories on the go.
I am working on 2 novels right now because I am so so busy. I am facing a very busy time of my life (blog on this possibly in the future), with many changes that I was not expecting. As someone who has to make a living with a job, job because writing does not, I have to focus on the real world as well as the imaginary world, which can be tough.
I have written a draft of one novel but I really need to sit down for a weekend and read through it, however, I am so busy I only get hour long periods through the day. Also, with a lack of an outlet, my brain is getting overloaded with ideas, and I can’t just write them down because I just lose them or find them stupid or no longer fresh. So with my hour long periods I decided to start another novel, my 4th: after one I self published, one that will probably never see the light of day and the two you are reading about.
And now here I am with 2 novels on the go.
The good part of writing 2 novels at the same time is you are getting more practice writing. Even if no one ever sees them, it is still good to work out what works and what does not. Plus, you can work on one, leave that to work on the other, and when you go back to the first one you can look at it with fresh eyes.
The downside is trying to keep all the characters in your head separated. It is like trying to keep two gangs apart before they start brawling. Also there are fears that passages might start sounding similar, but you will not realise because it all just blurs into one big happy process. This is when you find an editor!
But, if James Cameron can write Terminator 2 and Aliens simultaneously then why can’t I write 2 little novels at the same time? I should be lucky that I have the head space to do that. Although they could both come out terrible, some struggle to write 1 short story alone!
I guess, it is best to just work how you know, and never give up on that dream, even if working for that dream has to be squeezed into little moments throughout the day.
Because, to quote the end of Aliens “Can I dream?” – “Yes, honey, I think we both can”.