Can an entrepreneur successfully develop several businesses simultaneously?

On my journey, I've learned to focus on the present task; not to be all over the place, but to build one business idea at a time. I have a dream jar that contains a good handful of future business endeavors I'd like to pursue. For now, I must maintain focus on nurturing my current business and cementing the foundation for it. Once success has been achieved I can then move on to the next bright idea. Being a jack of all trades makes me a master of none.