Heroes of the Zeroes is Nick Rogers’ daily, alphabetical look back at the 365 best films of 2000 to 2009.

The Zeroes were littered with films portraying teens as Frankenstein monsters bolted together by prescription drugs and peer pressure — The Chumbscrubber, Rocket Science, The Wackness

Thumbsucker — Mike Mills’ 2005 dramedy — bested them by avoiding fingers wagged in caution or forced happiness or tragedy. Instead, Mills invested Thumbsucker with exceptional character development addressing opportunity costs of adolescence and adulthood.

Justin (Lou Taylor Pucci, letting sincerity cut through his deadpan) is a teen still sucking his thumb. It infuriates him and confounds Mike (Vincent D’Onofrio) and Audrey (Tilda Swinton) — well-meaning parents with their own inferiority complexes, yearning for bygone youths they’ve idolized beyond their realities.

After Justin is diagnosed with ADD, prescription drugs sharpen his focus, but this flipped switch seems almost too simple — “It was almost easier when he was always fucking up,” Mike says — and his authority figures wrestle over whether it’s sacrificing what makes Justin Justin. (Swinton and D’Onofrio are both excellent, with D’Onofrio exhibiting never-before-seen vulnerability.)

Keanu Reeves’ new-age orthodontist offers one of Thumbsucker’s many sublime moments of levity. But Mills insistently debates quick-draw medication without growing heavy-handed.

Drifting between extremes isn’t always a reason to sound the alarm. It could just be teen experimentation and experience — navigating a path to identity rather than resorting to biochemical ideals.

And Justin’s condition is only an awkward physical manifestation of how people cling to pasts as a security blanket. Thumbsucker doesn’t condone recklessly leaping, just the wisdom to never trick ourselves into thinking our current situation is the only answer.