Personally I had grown out of that habit a semester or two before undergrad QM (though "Modern Physics" and "Experimental Physics" were another story...) but th

Personally I had grown out of that habit a semester or two before undergrad QM (though "Modern Physics" and "Experimental Physics" were another story...) but there were still some hangers on. Maybe 1-3 in a class of 20-25? Neither the norm nor unheard of. From that point on the statistics were probably about the same in grad school.