You'll have a much better chance of being happy in life if you keep learning instead of pretending that you're fully developed and know everything. Nobody stops growing intellectually, there's always something new to contemplate. You can always discover more about yourself, others, and the world. Keep learning and you'll never run out of things to be excited about.
A big part of being happy with yourself is to continue the learning process. Be open to having new information enter your mind and be willing to change your perspective. People who are stuck in life aren't open to learning, but happy, fulfilled people are always excited about new knowledge and experiences.