"As long as you start, it's not too late" means that as long as you decide to do something, although it's late, you're not late or missed. It reflects a person's attitude towards people and his cognition of life. Each of us is not perfect. Many things may not be done in time, but we will always stick to it and never give up. As long as you have a good start, you will have the motivation to stick to it and you will be able to do things well.