Whats so different?

This summer has been kind of weird for me so far. When I moved back to Bremen I thought I would have a great time like I did last summer, but somehow things are different, and I cant figure out what. I was so happy last summer, so content with everything going on around me, I felt like I had so many options and unlimited freedom, every day was an adventure for me. But this summer, I just want every day to be over with, and I dont notice the little things anymore. The little things that made me so happy last summer dont have the same effect anymore. Take biking for example, that was such an adventure everytime I went out into the countryside to explore and breathe in the fresh air and feel the wind, but now I bike every day to work and those things arent quite as invigorating anymore. Its just a mode of transportation now. I dont see beauty in life anymore. I feel like I am just waiting for something, trying to get through each day as soon as possible instead of enjoying each passing moment. All that life had to offer me a year ago has seemed to fade away and now Im stuck in this monotonous rhythem of week and weekend, week and weekend. Wheres the adventure gone? Whats so different? Is it because I have a job that I am forced to go to from 7-4 every day? Thats a pretty big chunk of my day, and when the work day ends, I just feel exhausted and dont want to do anything the rest of the night. And all I do is worry now. Im forever worried about my car and what to do about that, worried about what Im going to do this weekend, or next month, or next year, or years from now. Im worried about what people think of me now. I dont have the same carefree 'go with the flow' attitude that I used to. And I hate it. I was happy then. Where did I change?