Academic failure I'm an undergrad student majoring in maths in my next semester. Up until the current semester I was able to get very good grades in almost every course and I had a grade average which I think would be placed at the highest position of any "regular" qualitative grade ranking system.
Alas, in the current semester I'm failing miserably. My grades have dropped to the point where I barely manage to pass the courses even at my favourite subjects. What's the point of studying if I don't learn?
The weird thing is I actually think I learned the subjects at which I didn't do good reasonably well.
During my time at the university I met lots of colleagues who thought they knew what they were talking about when we discussed courses that we attended together and they were actually clueless. Delusional even.
I feel like I am one of them now. 
How could I claim to know the subjects well if I barely passed and lots of people did better than me? Reason tells me I don't have a clue about what's going on, but my gut says otherwise.
I'm actually embarrassed about my grades and sad about I disappointing some of my favourite professors. The other day a professor at the department asked me where was I going to take my Masters. I said that I didn't plan on taking it and she told me that I should should because I'm a good student.
I felt awful about misleading professors like that. I wish they didn't notice me and didn't think I'm good, which obviously I'm not. How could I even think about taking a masters degree if I can't keep up with undergrad courses?
Has anyone here ever gone through a bad stretch grade wise for no apparent reason?
I don't even know why I'm posting this and know this well get closed really quick. It's OK...
 A: It sounds to me like you know why you're not doing well (but don't want to admit up to it), which is because you are not understanding the material that is being taught. As you said "What is the point of studying if I don't learn", suggests to me that despite putting time into it, you are unable to digest the material into a form that you can understand it.
[There could also be other reasons, just whether you want to consider them. Things like relationship troubles, roommate disagreements, loneliness, financial difficulties etc do affect your ability to concentrate, even though you might think that they are inconsequential.]
Let me speak from my experience. I did excellently well in my honors analysis class at the University of Chicago, which is supposed to be the hardest class. However, when I started on Algebra, I was in the bottom 30% of the class after the first midterm. I realized that while I could follow proofs from line to line, I didn't understand how and why it was put together in the way that was presented. I could see all the small details and work through the calculations, but completely miss the big picture of what is happening. Part of that is my Singaporean education stressed the ability to compute, much rather than to understand the theory. One clear sign to me, was that while I understood the definition of a normal subgroup ( $gng^{-1} \in N$), I had absolutely no clue why anyone cared about it. To me, definitions were merely a way to explain what we're working with. But in Algebra, the definitions are extremely useful and supposed to explain how to think about the bigger picture. It took a long time to learn to reorganize my thoughts to understand math in the bigger picture setting, rather than chasing after the minute details. (As another example, the theory of complex analysis is very very pretty, especially when taught by Narasimhan. However, all I could see was the delta epsilons that we were chasing, instead of seeing how everything fit together.)
As a side note, a lot of your colleagues do not really know what they are doing. Remember that empty vessels make the most noise. You should seek out those who actually have a deep understanding of the material, and learn from them. 

As the comments state, do not be afraid to ask for help. In fact, it is best to ask early and ask often (I'm glad you asked here, which is why I'm responding). It will seem daunting to talk to your professors about it, but they do understand what you're going through (at least those who are not lost in the clouds), and are dealing with similar students. At the very least, talk with the Undergrad chair in your university.
