People tell me Pensive Bear is sad, but I don't think so, I think he's just thoughtful. I'm not 100% sure what he's thinking about, because I don't speak fluent Bear and couldn't ask him for specifics. Nevertheless, I am a world-renowned bear whisperer, so I can tell you that Bear is most likely rigorously training himself in the art of lucid dreaming.
All bears do this. Hibernation is a months-long sleep, and it's a lot more fun if you can control your dreams. Why let your deep psyche determine your dreams, after all, when it'll probably just hurl you about its manic surreality, willy-nilly, and leave you anxious or frightened? No, better to take control of your dreams. Then you can be Superbear, leaping redwoods in a single bound, or you can just be a ladies' bear, or a bear vixen—the ultimate ursine seducer. And as many a renowned bear philosopher has said, perhaps all of reality is just one big dream? And if you are in a dream and can control it, is it really a dream? What separates it from reality? If you dream for months and months, who's to say you're not really just awake in another world, a world slightly more loosey-goosey than the one we call real?
Thus whisper the learned bears, of which Pensive Bear is surely one. I'm just telling you what I heard, folks. Bears. Hibernation. Starry Nights. Lucid dreams.
Makes sense to me.
If you have any other explanations for Pensive Bear's pensiveness, or ideas for what he might be dreaming, you are welcome to leave them in the comments section.