I'm at the age where I'm deciding what I wish to do with my life, and Physics so far is the only true discipline I have expressed even a modicum of interest in (granted, it's more so than just a modicum). The amount of time I have dabbled in modern physics is limited to my secondary school knowledge and my curiosity, and hence I don't have a rudimentary idea of the landscape of the discipline. How boundless is the field of Physics today, compared to how it was during the classical ages? Is it akin to the other physical sciences (specifically Biology) in that the holistic realizations have already been chanced upon, or is there sufficiently more to learn? As budding Physicists, is there anybody who regrets their decision to enter into this specific niche of academia?