This is really interesting because its the first time I’ve seen moodiness/irritability mentioned in association with the after effects of overtraining, or simply extended over-exerting. I’ve had the exact same experience. (Age 61) Have obviously modified and reduced severity of training regimen and still really enjoy long, exhausting rides (seems silly to admit it- as I cannot really explain that to non-riding friends but anyway). Recovery time needed is much greater now; more rest, and more time between intervals but the touchy mood, that is really an annoying and surprising by product.