Spot on. Everything is fun when the scale is small and the consequences don't matter, and everything is serious when the scale is large and the consequences matter.
Or the start of the project and completing the project. All those fun projects people start and never finish. All the fun stuff is done, it's the boilerplate that needs to be done to actually complete the project that is the "hard" part.
At the start, you can imagine all the cool things it does, once it's working you have to keep it working in the real world.