I marvelled at many things but I only learned one: that Europe is miserable in at least one thing, namely the morosity, Angst and bile of its intelligent and cultured people (or, really, every European, bar the Portuguese). Plainly put, if you are intelligent and / or cultured in Europe, you cannot be happy, you cannot be fun, it is inconceivable that you may smile or be pleasant. You must be possessed by the sullen spirit of Schopenhauer, you must look at the world throught the eyes of Raskolnikov, you must despise the world more intensely than that poor fictional New Yorker, Holden Caulfield, you must despise it at least as much as Nietzsche.
America taught me (Boston first and New York definitely) that you can be of a happy and kind disposition even if you are intelligent and cultured. Also, sullenness and grumpiness or pose, rudeness and obfuscation can hardly conceal emptiness and stupidity. In America. In Europe they are sufficient hallmarks of a true intellectual.