I want you to know that there is a HUGE difference between educated and intelligent. Educated means that you respond well to the school system and have the ability to manage schoolwork and the like. That's all good.Intelligence doesn't need and education behind it. It helps, yes, but intelligence can stand on its own. Just the fact that you are asking these questions, that you recognize there is nothing you can do to change the past though you regret it, that you have the ability to think about these things in depth shows me, just from this tiny post, that you have intelligence. And if I ever had a choice between being educated and being intelligent, I would pick intelligent every single time. So, NO. You are not dumb. There is proof, just in the fact that you can tell that it was because you were unmotivated - not because you couldn't understand what you were being taught if you put in the effort, that you are intelligent.