I've been writing on and off for decades with little luck in publishing. Evidently, there was too much off and not enough on. Internet workshops like sff.onlinewritingworkshop.com/ and www.critters.org improved my work enough to sell a few short stories, but what I really wanted was to publish a book.
An unrelenting series of rejections almost had me ready to give up. Then Lilly Press accepted my novel IMPLAC, an evil robot story. I was ecstatic, but Lilly went bankrupt and it was back to the slush pile for me. At least now I knew that some professionals valued my work. "Query Tracker" - http://querytracker.net/forum/ - taught me how to write a decent query, I sent out a batch of letters, and in 2010 Eternal Press accepted A VIRTUAL AFFAIR. At age 68 I would finally have a book for sale. Since then, I've had two more novels published, and am looking for an agent for my fourth.
It's never too late to pursue your dream.