I used to think that depression was time-limited too... then you see people, such as Robin Williams, who have struggled with it for decades and in the end, losing that battle. The thing is, depression isn't time limited. It's more like something that we have that we learn to live with. We can come up with different tools and mechanisms to deal with it, and we can even look at the positive aspects that it may have given us (for example, you've met so many beautiful people on PC!), but it's just yet another life-long challenge. However, the farther we travel down the path of life, the easier depression gets. You just have to keep... going.