It’s tempting to think that someone who has experience doing something for many years is skilled at what they do. But, repeated exposure to events is not what leads to expertise. Skill does not develop from experience.
For example, let’s say you can gauge the success of an auto mechanic by looking at rate of success in repairing cars. If your mechanic has been in the repair business for 10 years and has the same rate of success this past year compared to his first year, then your mechanic has 10 years of experience but has not developed expertise. And it’s probably time to find a new mechanic unless your mechanic somehow started with a very high rate of success (started with expertise).
If however, your mechanic had a success rate of 50% in his first year and 90% in his past year, that’s a sign of expertise.
Do not confused expertise with experience, experience is much more likely to simply be exposure.