Do not consider collectivists as "sincere but deluded idealists". The proposal to enslave some men for the sake of others is not an ideal; brutality is not "idealistic," no matter what its purpose. Do not ever say that the desire to "do good" by force is a good motive. Neither power-lust nor stupidity are good motives.
Where danger shews it self, apprehension cannot, without stupidity, be wanting; where danger is, sense of danger should be; and so much fear as should keep us awake, and excite our attention, industry, and vigour; but not to disturb the calm use of our reason, nor hinder the execution of what that dictates.
Well . . . he lets it ruin his life. he gets so obsessed with going after the one thing that hurt him that he loses sight of everything else. he becomes isolated from everyone and everything. paranoid. he feels like he can't trust anyone around him ever. in the end, he loses everything, even his life. and for what? total stupidity, if you ask me.