You can't afford to be obsessive... it means time and money now, and it's not your time and money, it's someone else's. That changes things. I was talking with a coworker a few weeks back about how he felt when he saw an interview candidate with a perfect 4.0 grade point average. "It sounds crazy, but I feel more comfortable with seeing a 3.5-3.8 range," he said. "When I went to school, the 4.0 guys were the ones who'd work an assignment twice as long if they thought it meant they'd get a 99% instead of a 93%. It was worth it to them. They come work here, and want ten people to check their drawing, or call five meetings to get 20 opinions on whether our error message should say FUEL PRESSURE LOW or FUEL LOW PRESSURE, and they're so afraid to tell their boss a date when they'll be done with an assignment they freeze in scheduling meetings. That doesn't work here."
On the other hand, attention to detail is important. In college, you get to the end of the semester and you're done. You turn in that last paper and whatever it got you, it got you. It's different in the real world... you can't take a C on something. It will come back to haunt you. Unhappy customers will call you. The technicians can't skip a line here and there on their verification test. If your coworkers find a lot of mistakes in your work, you look really bad. I was really lucky in college to have taken a good technical editing class that taught me to go over writing with a fine-tooth comb, so to speak. Reviewing your own work is an important skill.
I realize it may sound weird for me to say "there's a balance" because I work in aircraft, and if any industry does perfection to EXTREMES you'd think it'd be us. But honestly, we've been making airplanes fly for 100 years now, it's not as big a deal as you think. The "make sure the airplane is safe" discipline in my industry is actually really boring... pages and pages of numbers and analysis, databases, reliability records.
At any point in the evolution of products we're really only making tiny deviations from previous designs, and 99% of my job isn't crucial things. I plug in boxes. My job is mostly communication, scheduling, paperwork, converting formats, translating. As I told a group of college students once... "I make a lot of block diagrams." Sometimes we do find a drawing with "superseded" spelled wrong, but we can't sweat it if it won't change the way the airplane works, it's not worth taking up everyone's time for a revision.
Good work matters, the schedule also matters. Both matter in totally different ways than they did in college.