What project(s) have you started and found to be bigger than you expected?
The wife decided it was time to paint the hallway. This required emptying the hallway. Which was a task she expected.
She then needed to remove the popcorn covering on the walls, which was much larger than she expected. Even though I bought a power wall sander for her.
The result was no more popcorn/textured walls. But there were dings, scrapes, and other damage on the walls. We could have just painted over and it would have been ok.
I decided we needed to apply a skim coat. Which meant I had to learn that what I wanted to do was a skim coat. Then I had to learn how to do it. Then try and fail. Then try again and fail differently. Something about having just the right amount of water in the plaster.
I have 3/4s of one wall completely ready for the primer. The the rest of that wall and 2.5 other walls are ready to be sanded, and I still need to apply the skim coat on about 60 sq ft of wall.
Damn that is a skill I do not have.
Any project involving paint, water, or electricity will take longer than expected and be more involved.
For projects with combinations of these factors, the effects are multiplicative, not additive.