The brutal truth of it is that while there is beauty in the craft, in the end shipping is what matters. Getting things in front of the people that need them.
There's a nice concept in theater that says, effectively, "if you blow a line, don't broadcast it to the audience." The subtext of that is, simply, the audience doesn't know any better and what they don't know, won't hurt them.
By and large, this applies to many fields, and certainly to software development. The users, in the large, do not care over a huge amount of stuff that we, as practitioners, care about.
We're in a results business. The users care that they get the report they want or can update the data they're supposed to. How that's done, in the back end, is filed under "blah blah blah".
The reason this is important is not as an excuse to do crummy work, or to not be passionate about the minutiae that consumes us, but to be cognizant that as long as the end result is functional and capable for the user, it's OK for the processes that get to that point to be a bit messy. Don't beat yourself up over a lot of the things we beat ourselves up, or criticize others over.
Ship. Get your code in front of users, interact with them to make their experience better. We are in a service industry. Strive to be better, but you only get better by shipping, and moving on.
The confidence is that, for the most part, "it's just software" and you can fix it. You can change it later. You can correct mistakes.
Another saying is that you're not a professional until you've lost production data. Thankfully in our work, loss of production data rarely kills people, in contrast to the path of becoming, say, a doctor. If you are in an industry where people can be hurt, then that's going to be more rigid, for obvious reasons.
I have lost data, I have been SCREAMED at by clients, I have stood under the withering "What has just happened here" glare from management. It happens. Ah, the warm camaraderie of being thrown into a data entry pool to help rekey some of the 6 months of data you destroyed. A cold truth in our business is that it has to happen, as we only learn through practice, and through practice, sometimes we miss.
But to do that, we have to ship. We have to get the work out there, "I don't test often, but when I do, it's in production". Sometimes you just got to open the firewall up, let the traffic in, and see what happens.
A cynical view is the that the more we ship, the more we learn what we can get away with. There's a truth to that as well. We're all victims of not listening to "you're not going to need it". For all sorts of values of "it". But that doesn't mean we can't keep those concepts close, practice them as best as we can (because, truth is, sometimes you do need it!).
Through the work, and shipping, you learn the balance, and get more comfortable with it.