I hate not being intelligent enough for leetcode

I’m a CS student and I have done around 500-700 hours of programming. It’s been really bugging me how leetcode problems don’t click for me, even the easy ones, it took me like 20 minutes to do Two Sum and that with brute force. Roman to Integer took me hours, I feel so disappointed and undervalued to see colleagues who have solved hundreds or even more than a thousand of problems. It’s like my brain is just not working properly and its designed to be stupid. Those who experienced the same, what did you do?