I have been doing LC for a while now, was pretty struggling with easy and medium when I started, now I am quite comfortable with most medium questions.

But lately I found myself getting so stuck at HARD problems, a lot of times I just couldn't work out the intuition behind it to solve the problem, like this one here https://leetcode.com/problems/distinct-subsequences-ii/solution/

Like i know it's DP problem, but i just couldn't work out the state transition forumula, and I am getting really demotivated now. i see all these people jumping into the contests, and they probably haven't seen those probelms before either but they are ok with solving them.

is it just that some people are smarter than others ? maybe i am just not smart enough to get through the interviews with companies like google ?

how do you conquer the HARD problems ? is it still just a learning curve end of the day ?