I just about cried laughing when I saw Fred Wilson's version of Paul Graham's start-up curve. It's not just true for software or tech companies - it's true for nearly all entrepreneurs.
The difference is, if you've been through the "Crash of Ineptitude" before (which invariably occurs right after the internal high of "Releases and Improvements"), then it doesn't hit you nearly as hard as it did with your first company.
Having both staff who saw me through the first one (thanks Ron!) and a current business partner for whom this is a first one, helped me notice the difference in my reactions.
The second time around, SNAFUS (from WWII soldier slang, "situation normal, all fucked up") just don't freak you out the same way they did the first time. For example, today when a customer announced his decision to cancel his account to the entire customer email list instead of to customer service directly (I choose to assume it was by mistake and he didn't mean his message to go to all other clients of that service), I laughed. Shit happens. And then when our service rep replied to the entire List, instead of to him directly, I felt empathy for her, instead of outrage. I knew she'd feel awful about her mistake already and she didn't need my anger on top of that.
This is not to say you let things go, or don't try to control things even better, your second time around. I've been better this time at foreseeing potential problems and training people to avoid them. We have a lot more how-to docs now, and tons more training.
But I accept that there will be SNAFUS. There will be situations we should have foreseen and fixed before they became problems (or in the words of a former mentor, "opportunities".)
If we stay customer-centric, customer-focused, and apologize wholeheartedly, everyone's going to be OK. And if they are not, well, that's part of doing business too. Sometimes you will screw up. It's inevitable. Put all the measures you can in place, and then pray you've done a good enough job of solving customer pain with your product or service that they'll forgive you. When you inevitably fuck up. Because we're all human. Even the second time around.