Advice for juniors who fear they are spending too much time on new assignments…

Im a junior litigation associate and I’ve been told it’s normal to be slow when working on new assignments, but it feels embarrassing and kind of alarming when it almost always takes double the amount of time I think it would take based on the senior’s/partner’s estimates. Most things I’ve gotten faster with the second or third time around, but others like research or finding cites can take hours… for this, I’m hoping I get faster once I am more familiar with the niche areas of the law, but also finding that hard to believe because there’s so much to learn!!

I know a part of my slowness is that I am very detail oriented, double check everything, and want everything I submit to be 100% effort. But how do you balance this with being efficient? Do you just call it at 90% the more senior you get?

Do partners get mad if they see your long hours billed on research? I do pause and ask for help mid-way, especially if I have a time cap, but most of the time, I don’t get a time cap or it’s more of a “just get it done by tonight or tomorrow” situation.