College is a lot less about being smart than people tend to think, and much more about working hard. If you can get admitted into A&M, you've got the mental horsepower to succeed here. The only thing separating you from that is work ethic.
Pretty much every undergrad degree just goes over the basics of a field, so there's not going to be any kind of brain-warping stuff that's just beyond your ability to comprehend. At the same time, like Elicitd said, there's some stuff that isn't obvious right away and that you're frankly going to need to struggle with a bit before you understand it. This can be a shock to students who just cruised through a bunch of easy, intuitive stuff in high school.
What screws over a lot of freshmen is that they take the old high school approach of "never study outside class" + "copy homework last minute" + "take all the tests cold" and then wonder why they got an F on their first exam. College requires a lot more effort on your part to stay on the ball vs HS classes where everything just gets spoon-fed to you, and I'd say out of the freshmen who fail, the vast majority simply didn't study enough vs just not being smart enough to hack it.