When I got out of college I had a very incomplete view of what getting a career afterwards entails. I didn't get an internship, I didn't go talk to my professors after school, I didn't care about clubs (because I didn't participate in clubs in HS). Career center wasn't very helpful for art majors. I did not live near campus, as I took the train to commute daily.
I'd be thinking it's okay if I didn't get an internship because I've already had relevant part-time experience at that point. So I just hopped online to apply to more jobs. And figured, as long as I'm professional and do my job well, everything will be fine.
Also, it was difficult to foresee the appeal and benefits to networking for your career, because I had trouble making friends in college and in jobs, and I fell back on my high school friends for social activities. Whether I was working as a cashier at Sears or building web pages for a local client, my social life and work life were always separate.
I found most of my classmates in art classes difficult to relate to. There are no clubs or social groups for art majors, either. This turned me off from attempting to make friends in college and I stuck with my old high school friends. I think it's harder to appreciate the benefits of networking if you have a hard time finding people with common interests. So I missed the forest for the trees.