What are some of the more subtle symptoms of dehydration that gravel riders might overlook, and how can we train ourselves to recognize them before they escalate into full-blown dehydration? Are there any physical or mental cues that are more relevant to gravel riding specifically, given the variable terrain and often unpredictable weather conditions? How do experienced riders distinguish between dehydration symptoms and fatigue or bonking, and what strategies do they use to stay hydrated on long, remote gravel rides where water stops might be scarce?