This thread is giving me hope! I'm building an RV-8, and in the beginning I figured I was padding my estimate when I thought the build would take 2,000 hrs over 4 yrs.
I now tell people that I'm in the eighth year of a four year project. If it takes me the full 8 yrs, I'll have spent 4,000 hrs of construction time. I'm detail-oriented, so I keep careful track of my construction time. I only log time I'm actually in the shop making progress, not time I spend shopping for supplies, researching how to do something, making decisions, problem solving, etc. I'm not trying to build a show plane and I have stuck to the plans in all but a few items (stainless steel cooling ramp, Grove gear, avionics access panel, fuel gauge mount, canopy bonding, rear stick cover, Titan engine, and I covered my instrument panel and consoles with carbon fiber to match my prop).
I'm perhaps a little more meticulous than the average builder, which I'm certain slows my progress, but I'm okay with that. When I got to the electrical stage, I realized that I'm a slow builder. After I'd spent an hour or two in the shop, I'd look back at what I did to update my logs, only to realize I had installed and tested just a few wires. It shouldn't have taken that long, but it did. That seems to be a theme with me. I keep saying, "It shouldn't have taken me that long to do that" but it does, and so it continues.
All I can really control is when I drag myself out of bed and head to the workshop each morning. I've long since given up on my initial timeline, now I just try to work on the plane 10 hrs/week, and I normally work on it every day I'm home. If I do that enough times, the plane will eventually fly.