This was my first exposure to probability. I only took one semester out of a two semester sequence, but that exposure really helped for graduate school in statistics. There's a ton of applied practice problems, but few proofs. Some sections could be clearer, but it's a way better introduction than Casella and Berger, which is an amazing text, but not as a first exposure. Pair this book with a good professor and you'll learn a lot and be left with more questions