Step 1. Try safe things, stop lots of things, mostly watch films that look pretty with one or two favorite
Step 2. Crazy forages into film writing/review catalogs to see what's out there. In actual film watching, tries a few new and alien things based on multiple positive recommendations.
Step 3. More literate in favorite elements of films and given era's best bets, therefore able to make informed decisions about less known films that may go against trusted authorities. Still triple checks every film summary and agonize over cast lists and and ages of beloved stars. More researching than watching.
Step 4. Acquired tastes have ballooned into expanded tastes. Like really expanded. Lots of experimentation.
Step 5. Enlightenment. Otherwise known as the sweetspot between obsession and apathy. Summaries and subtitles are for lesser beings. Eras viewed as porous ... one era appears to bleed into the next with different buffets of delights [and potential food poisoning] appearing year by chronological year. Happy to try anything once, but quite unapologetic about likes and dislikes. Small positive elements are elevated to huge perks. AKA Film Judgment Bar = [now] extremely subjective. Happy place to be, but fanatic will appear snobbish to those in earlier steps and will likely feel that no one (ok, maybe one or two people on the other side of the world) likes what he or she likes. Secretly takes pride in this idea. This step is really a coping mechanism to quench the insatiable thirst for new experiences. However "inferior" these new experiences may seem at earlier steps, they suddenly seem like the only important thing to do after other options have been exhausted.
[Era by era, region by region, niche by niche, this process may be repeated ad nauseum. Also, film fanatic can sometimes lose place in steps and revert to earlier step a la "watcher's block."]