Observing other people improve their lives can be a powerful source of inspiration. Eight experiments explore the power, limits, and reasons for this power of personal change to inspire. We find that people who have improved from undesirable pasts (e.g., people who used to abuse extreme drugs but no longer do) are more inspiring than people who maintain consistently desirable standings (e.g., people who have never used extreme drugs to begin with), because change is perceived as more effortful than stability (Experiments 1a and 1b). The inspirational power of personal change is rooted in people’s lack of access to the internal struggles and hard work that many others may endure to successfully remain ‘always-good.’ Accordingly, giving observers access into the effort underlying others’ success in maintaining consistently positive standings restores the inspiring power of being ‘always-good’ (Experiments 2–4). Finally, change is more inspiring than stability across many domains but one: people who used to harm others but have since reformed (e.g., ex-bullies or ex-cheaters) do not inspire, and in many cases are indeed less inspiring than people who have never harmed others to begin with (Experiments 5–7). Together, these studies reveal how, why, and when one’s past influences one’s present in the eyes of others: having some “bad” in your past can be surprisingly positive, at least partly because observers assume that becoming “good” is harder than being “good” all along.