Specializing in certain breeds in grooming?

I know my aunt's cousin has a grooming shop specializing in Poodles...now, does that mean that she prefers and is better at Poodles than other breeds, but accepts all, OR that she only grooms Poodles?
Can you pick one breed and have a grooming shop for them alone? To me that seems like you would have barely any business?! Lol but I'm very 'green' in this area so please excuse that.
I was thinking of becoming a groomer...maybe even get into mobile grooming. I'm just wondering about the job. I think some people on here are groomers...what's the job like? To me, it seems like there would be a lot of things to memorize in terms of how to cut certain coat textures, lengths, etc. Bathing and ear trimming, ETC, doesn't seem too complicated, although I'm sure I'm missing lots here! Salary, hours, pros and cons, etc?
Thanks so much [:)]