Possible Clues:

• More sullen
• Being more impulsive, pass on when visiting heath
• More likely to sulk
• Peter out in Ilkley, maybe more miserable
• Go west in latitude, going west, getting darker
• More apt to pout
• Fade away in desolate place that's less cheerful
• Showing a more brooding ill-humour
• More erratic
• Less likely to laugh