Dear 100 Hour Board,
Many times when people don't like the way the look they are advised not only to work towards improving their appearance, but also to accept themselves despite their imperfections. How do you apply this advice to intelligence? How do you like yourself when you're dumb? Yes, you can always educate yourself more, but how do you become accepting of the fact that you're not terribly smart?
Nimrod, and not the mighty hunter
You say that you're not that smart, but which kind of intelligence are you referring to?
A lot of the time when people say that someone is intelligent they seem to primarily think of logical/mathematical intelligence, or intelligence in an academic setting. However, as it turns out, there are 9 different types of intelligence, none of which I would say are more important than another.
Note that your intelligence in any of these 9 areas isn't static. If you want to develop your logical intelligence, practice solving logic puzzles, and even try out taking a mathematical proofs class. If you want to improve your social intelligence, devote more time to interactions with other people. Your mind is similar to your body in that you have the power to keep it "fit" with respect to any of these kinds of intelligence. How that fitness will outwardly manifest itself will be different from person to person, and honestly, I find that variety to be beautiful.
I think the first step to accepting your intelligence (in any area) for what it is involves acknowledging every kind of intelligence you possess. Are you talented at introspection, visualization, expressing your thoughts, hand-eye coordination, reading other people, music, understanding nature, or pondering existential questions? If the answer is "yes" to any of those, then you possess that type of intelligence.
Everyone living on this earth has been blessed with certain gifts and talents. Perhaps yours aren't what you would wish, but that does not take away from their intrinsic value, or from yours. Regardless of what score you would get on an IQ test, your worth is infinite. Look for the beauty and worth in the talents and different kinds of intelligence you do have, and work on the skills you want to have but don't quite yet.
Finally, don't compare yourself to others. If you have a nagging voice at the back of your mind telling you you're just not as smart as so and so, you're not good enough, etc., directly confront that voice. Evaluate it instead of blindly trusting it. Perhaps your response to that voice can be to say, "Yeah, [insert type of intelligence here] isn't really my thing. But that's okay. I am good at [insert different type of intelligence]. I am still a good person, and have infinite worth no matter how good or bad I am at [first type of intelligence]."
One of my professors did a little exercise in class that was kind of cool. It went like this:
First, think of the smartest person you know.
Second, think of the person you admire most.
The vast majority of the time, they aren't the same person. Most worthy of our admiration are people who have compassion, kindness, patience, determination, courage, generosity, and all of the other things that make someone morally good. Intelligence is just one aspect of a person, and it is not the thing that makes someone great. And if you're not convinced by that exercise, Hermione Granger agrees with me and she is always right:
"Harry - you're a great wizard, you know."
"I'm not as good as you."
"Me! Books! Cleverness! There are more important things - friendship and bravery..."
You have so much to give to the world.