Because the main box is divided into three smaller boxes, one for bow, one for stern, and one for midship. You can build them in any order, or they can be built simultaneously by you and your friends/family. They included a brick separator in each sub-box.

That game cartridge mechanism is satisfying.

I’m guessing OP was talking about set #10497 Galaxy Explorer with 1,254 pieces.

Maybe two weeks of nightly building after work while watching TV.

Titanic, and no. I looked at getting an LED kit for it, saw how much I’d have to disassemble and decided not to.