I think it does pass faster as you age. You work all day, go home and you have to get things done. And then the weekend is to recuperate, get more things done, and try to have fun--if you can squeeze it in.
When you're a kid, at least for me, everything seemed in slow motion. The school day and the school year seemed so long. I couldn't wait until my next vacation. Halloween and Christmas were holidays to look forward to, and I couldn't wait for them to happen. I enjoyed my birthdays when I was young. I'd get gifts and a party, but now, I don't like to celebrate them anymore. They're just another day, and unfortunately you're a year older, even if you don't feel it.
And getting older means more deaths you have to deal with, family and friends. Yes, time does pass fast.