I feel like at this point, DSP understands that it's not going to be a cakewalk, but he still doesn't grasp the entirety of the situation.
Like the IRS. He's completely nonchalant about the fact that he can't pay his 2019 taxes. He just shrugs his shoulders and goes "oh well, they'll add it to the payment plan." He legit doesn't understand the seriousness of owing the IRS five-figures and two years worth of money and he won't until the IRS starts actually coming at him harder.
It's like the dog in the house on fire meme. Everything will be fine for DSP until he actually catches on fire himself. The fact that Rome is burning all around him makes no difference to him. He can only think in the present, and he's not presently on fire, so he doesn't care that the fire is rapidly approaching him.