First, realize you are not alone. The vast majority of Violin Lab members fall into two categories: adults who are complete beginners; and adults who played for a while as a kid and want to get back into it. Your experience as a child, even if it was years or decades ago, will be helpful. Think riding a bicycle. But it will be important for you to revisit many of the fundamentals that will lay the foundation for an enjoyable experience. That's part of what Violin Lab can help you do. For example, if you played violin for a few years and quit after Suzuki Book Three, we don't recommend buying Book Four and starting from there. You'll need to reacquaint yourself with some of the basics of playing, such as a proper bow hold, good posture and even good practice habits. Violin Lab can guide you through this. Some things may come back to you right away, as if you never stopped playing.
Other things will be a struggle and a source of frustration as you remember yourself zipping through something as a kid that today makes your fingers ache. That's why it's important to start fresh with the fundamentals, and gradually work yourself back to the point where you left off as a kid. It's not only the right way to learn, but it may also help you avoid some of that frustration that could cause you to stop again. So strap on a helmet and some knee pads first, and go for a leisurely ride around the block. After a while, we'll find that little bell you had on your handle-bars and maybe put some playing cards in your spokes. Enjoy the process of getting back in shape. It may be a while before we're chasing Lance along The Avenue des Champs-Élysées.