Many of us on SM were ignorant until we found this forum and learned what we wish we'd known BEFORE getting our furbabies. So you are in good company! I wish you and Bentley many, many happy, healthy, loving years together.
When you do get to the point where you have investigated what a puppymill is you can take it upon yourself to begin informing friends, neighbors, family, acquaintances, etc. about petstores and puppymills and help spread the information so others don't make our mistakes, however inadvertently.
When I take Pico out I get soooo many questions about what is he? oh, he's so cute? I want one!, etc. Many times the encounter is so brief I don't have time to get into the petstore, irresponsible breeder, puppymill conversation so what i have done instead is.......printed out a flyer briefly describing puppymills and the role of petstores, brokers, flea markets, etc. I give the Prisoners of Greed website, the Spoiled Maltese website and urge them to research this breed before purchase.
This way, even if they decide on another breed, they still learned what they need to know to make a responsible purchase. I keep a stack of these in my car, in my briefcase, and a couple folded up in my purse. Every little bit we can do helps. My Mom always said, "pennies make dimes and dimes make dollars". I believe this applies to just about everything.