Do you know all of the job boards (CV Library, Reed, Indeed etc) that your CV is on?
And, when was the last time you checked these job boards to see which version of your CV is on there?
Many recruiters have access to the CVs contained on job boards. They use this information to see if they can find relevant candidates for their jobs, so if you have an out-of-date CV on there you could be missing out on being approached about vacancies that you are a match for.
Alternatively, if you keep being contacted about jobs that you have no interest in, it could be because an old CV is still visible on these job boards.
Next time you are approached ask the recruiter where they found your CV, then you can log on to the job board and edit or delete the CV as you see fit.
A fresh edit of your CV on a job board could be all you need to do to alert a recruiter and secure your dream job.