An interesting analysis by Ziogan, but I feel a more computational analysis is called for.

Here is how to sleep with 10,000 women in four simple steps:

While(NumWomen is less than 10000){
  Find woman
  Have Sex
  NumWomen = NumWomen + 1

Now, we know we want to sleep with 10,000 women. We also know there are 365.25 days in a year. Let's say we start our adventure aged eighteen. Also, we can assume the project will need to be done by the time you are 35. That gives us 17 years for our project.

The UK police force has a sickness rate of 11 - 12 days per officer per year. We will a similarly risky ocupation, and say we have 9.25 sick days per year. The total project will have 6,052 days. We want to have sex with 10,000 women, so that means we will be having sex 1.65 times per day, or 11.57 times per week.

Assuming we have a 9-5 job, 1 hour total traveling per day, 30 minutes for breakfast and tea, and 7 hours sleeping, that leaves us 8 hours 30 minutes free time, and that works out as 5 hours, 8 minutes per woman. If anyone has any idea how to get a woman from 'absolute stranger' to sleeping with you in 5 hours, feel free to add a writeup.

In conclusion, any guy claiming to have slept with 10,000 women is either: (a) old, (b) lying or (c) Something like a male prostitute, where he has sex several times a day, every day.