Most people who do not actually log their dives over estimate the number of dives they have done, usually by quite a large percentage. This can be worked out when you divide the number of claimed dives by the years they have been diving and then by how many per week they would have had to do. For example, a person claiming 12,000 dives in 24 years means they dived an average of 500 dives a year or almost 10 a week. When you take out bad weather, holidays, time off etc, unless the person is a professional diver working in a location where they dive most days of the week, then the numbers will not be anywhere near that amount.
I knew someone who claimed they did 200 dives a year at a particular Australian location every year for 10 years. It was impossible as he lived 200 km from the location, worked in an occupation that meant he did not get weekends off for half the year and could have only got a dive on weekends. Take out the fact that 40% of the time you cannot dive that location due to weather, then his claim was BS.
The majority of people I regularly dive with do log their dives. We have many with over 2,000 dives and dozens over 1,000. Personally, I did dive 4,301 yesterday, all logged and all accessible for people to see on the internet. None of my dives have been as a professional either.