Maybe it's because sycamores surround our North Berkeley library, and lined many of the older streets in colonial Germantown, where I grew up, but I just have that association of them with ancient wisdom and knowledge.
A Russian friend of mine studied with a shaman in her native land, and she takes people on nature walks and teaches about trees; how to interact with them spiritually, what each variety's special gifts are, and how to identify the charisms of individual trees. She never mentioned sycamores in any of the walks I took with her, but I must say that when I spend time with them, I definitely get a studious vibe, a great love of knowledge and the arts. The Humanities, as we might say, and not particularly the sciences.
When I look up sycamores in my various sources on symbols, I don't find much. Apparently they were called 'pharoah's fig' and were considered sacred in Egypt. That makes sense, because they do look like tall massive fig trees, so they are the King (or Pharoah) of Fig-trees, I suppose. Also, it's mentioned that in the Bible Zacharias climbed the sycamore to get a better look at Christ, and is thus a symbol for becoming god-mad. But somehow these don't describe what I experience in their presence. I suppose I'll just have to keep looking, and in the meantime, continue to enjoy the deep feelings of the love of 'study,' of reading and writing, that I have around their stately selves. Especially in Autumn, but then Autumn is the time to celebrate the goddess of learning, both in India (Navaratri and Vijaya Dashami) and in the U.S.
By the way, there is another Festival of the Trees going on, and the links are listed at the Hoarded Ordinaries site. Click the link above or go to the side-bar link.