In my experience there are only two estimates that consistently matter: "really really easy" and "really really hard." If your Product Manager thinks a task is easy but it's actually hard, you have to teach them so they can decide if it's really worth the effort right now (or at all). If they think a task is hard but it's actually easy, you have to teach them so they can decide if it should be prioritized for a quick win.
8 years, I still can't estimate. I have a feeling at 30 years, I still won't be able to estimate.
Read and ye shall as estimate as well as any engineer who walks this earth. ocw.mit.edu/resources/res-6-011-th...
In my experience there are only two estimates that consistently matter: "really really easy" and "really really hard." If your Product Manager thinks a task is easy but it's actually hard, you have to teach them so they can decide if it's really worth the effort right now (or at all). If they think a task is hard but it's actually easy, you have to teach them so they can decide if it should be prioritized for a quick win.
Obligatory: xkcd.com/1425/
Is that 30 estimated years? :D
Almost 20 years in business and still cannot estimate.