Being smart is overrated. Being nice is underrated. Everybody is smart. Not everybody is nice. Some very smart people are not very nice. Anybody who is very nice is also very smart. If you are very nice you recognize how wonderful it is to make other people feel good. You see the value in other people. You see that your moods and problems do not need to interfere with how you treat other people. You know how to love. That is extremely smart.
Everybody is smart. We all express our intelligence in different ways. Some people know a lot of facts, some people draw amazing pictures, some people can do math, some people can understand emotions, and some people can appreciate a sunset. Most people are good at many of these things. Smart is common. Society teaches us that smart is rare. When we go through educational systems we get ranked on how smart we are based on a limited measuring system. Some very smart people come out of school feeling stupid, because they were never properly measured.
Nice is not measured at all. Being extremely nice may not even gain you social acceptance. Being nice though, is one of the most important things you can do. Being nice in your interactions with people will make your life fulfilling. Being nice has a cumulative effect. You will attract great friends, you will have good relationships, you will find happiness.