Handwriting vs $\LaTeX$ Until a few months ago, I would handwrite practically all the math I wrote. However, I've been using LaTeX to typeset notes, assignments, etc quite extensively since then - to the point that I've started noticing that I'm only able to absorb the material fully once I type it up now. Even if I'm reading up notes and then writing proofs down by hand, I feel like I only gain a full understanding of them after typing them up. Is that something that others experience? Is this a bad sign, since I suppose handwriting math is still a more efficient way of learning (rather than typing everything)?
 A: I've certainly felt this, as well. I'm an undergrad math major and started typing up homework and notes over the last year or so. I had similar concerns, so my solution was to write up the entirety of my homeworks and notes extremely clearly before going to type it up in LaTeX. At first, I tended to write plenty of equations on paper and then fill in textual details when typing; as I'm sure you know, typing it up often requires more context. I found that filling in the details by hand (sometimes excessively) quashed this concern for me. 
A: It is a good idea to learn $\LaTeX$, especially as an undergraduate mathematics major. While writing proofs, I prefer to write my initial attempts on paper before formally writing up the proof in an Overleaf document. I typically write two or three drafts on paper before combining all of my ideas into a single Overleaf document.
This strategy has gotten me through all of my mathematics courses (including the prelim/qualifying exams, which I took last year). However, I still do handwrite all of my course notes. This is because I haven't found an efficient way to type up lecture notes at the same pace that the lecturer writes material on a chalkboard. A bunch of students can type up lecture notes in class and listen to the lecture, but I prefer to handwrite my notes and then later type up a $\LaTeX$ document.
In general, I would recommend doing all of the mathematics on pencil and paper before worrying about a $\LaTeX$ document. My strategy is to purchase a bunch of Mead spiral notebooks which contain $70$-$100$ sheets of lined paper. I typically go through about $1$-$2$ notebooks a week. In the notebooks, I summarize all of the course notes and I also try to write every proof that I read in my own words. When one of the proofs is complete, I make an Overleaf document and fill in the details.
Learning $\LaTeX$ will also be beneficial later in life. You could create a personal website and add all of your lecture notes under a course notes subsection. Also, if you are interested in publishing some of your work then it will be easier to write your first publication if you are familiar with $\LaTeX$. 
