And yet I was full of anxiety. I don't think that's being melodramatic. Think about it. You've put many hours into building the model, making sure the seams are relatively smooth, ensuring everything is aligned, adding detail beyond what's provided in the kit, applying a smooth coat of paint, blah blah blah. In addition to the time investment, you may have easily put over $100 in the model.
Applying decals is that final, yet crucial, step in the process of building the model where you don't really get a second chance. Screw it up now and you may find yourself repainting part or all of the model. Or buying a replacement set of decals (assuming they're not out of production). You should be nervous!
Ironically, a few hours after I applied the decals to the F-15 my life-long friend David called me on the phone. His most recent project, a Hasegawa 1/48 TA-4J in those pretty white and orange training colors met a tragic fate when several of the kit decals refused to adhere to the model and the national insignia refused to settle over those problematic vortex generators on the wings. He's decided to repaint the model in adversary colors, and frankly I can't blame him.
The decals on my F-15 are complete now, so from here it's just a matter of sealing them, weathering the model, and assembling it. Anything could still go wrong, but one more crucial process is behind me. Why must the hobby fill me with so much anxiety?