Based on the provided information, the idea that the suggestions in Passage 1 are based on is:
The way we perceive our circumstances drives our moods.
The passage mentions various activities and practices that can transform one's state of mind and contribute to positive well-being. These suggestions, such as keeping a gratitude journal, surrounding oneself with loved ones, and engaging in altruistic acts, are all centered around how we perceive and approach our circumstances, indicating that our mindset plays a significant role in shaping our moods and overall well-being.