He used his arm to save lives, not destroy them, including his own, a hero, vs heroin.
His sacrifice was not a one-time act, a lifelong giving. And yet he was able to do so effectually because of a rare component he was given, and could donate in relative ease, and receive gratitude for it by many.
Meanwhile there are others who give of themselves in life long greater (in terms of sacrifice, effort and pain) service, and who may not see how effectual it is, but God will reward the elect according to their labor down in Christ, both in terms of quality quantity and and sacrifice. Yet it is all of grace, as in salvation, for both motivation and ability comers from on High. To God be the glory.