I've been a full-time pro for more than 40 years, and part-time before that.
I have probably averaged 5 nights a week, plus a few doubles.
40 years times 50 weeks is 2,000 weeks.
2,000 times 5 is 10,000 nights, give or take a thousand or so.
Those of you who have done 20,000 jobs are truly workhorses!