Does the hook grip always hurt?
Yes. And no.
Yes, because of course there is quite a bit of pressure on your thumb, and at first, you will find this to be quite . . . uncomfortable. If you feel like screaming like a 3-year-old at the end of your deadlift work set, congratulations, you’re among friends.
No, because eventually you won’t notice the discomfort nearly as much as you do at first, and more importantly, you will stop caring. You are a lifter, and you’ll have more important things to complain about, such as having to unload all the plates from your massively heavy deadlift that you just pulled . . . because you used the hook grip. Everyone who uses it adapts to it, and you are not a special snowflake. Yes, you.