Well, sir, I think it's just as well that they are being…

““Well, sir, I think it's just as well that they are being phased out of the war effort, and that we are now going to detonate the supernova bomb. In the very short time since we were released from the time envelope-' 'Get to the point' 'The robots aren't enjoying it, sir.' 'what' 'The war sir, it seems to be getting them down there's a certain world-weariness.' 'Well, that's all right, they're meant to be helping to destroy it.' 'yes, well they're finding it difficult, sir. They are afflicted with a certain lassitude. They're just finding it hard to get behind the job. They lack oomph.' 'What are you trying to say?' 'Well, I think they're very depressed about something, sir.' 'What on Krikkit are you talking about?' 'Well, in a few skirmishes they've recently, it seems that they go into battle, raise their weapons to fire and suddenly think, why bother? What, cosmically speaking, is it all about? And they just seem to get a little tired and a little grim.' 'And then what do they do?' 'Er, quadratic equations mostly, sir. Fiendishly difficult ones by all accounts. And then they sulk.' 'Sulk?' 'Yes, sir.' 'Whoever heard of a robot sulking?' 'I don't know, sir.””

— Douglas Adams