Learning Common Lisp

I'm challenging myself to learn Common Lisp in one month intervals (current period is November 27 - December 27 2018). I will be posting every day inside this repository detailing what I did that day in order to advance my knowledge. You'll be able to find a list of the posts here. If I miss a day, you'll have the chance to have me send you $5. Just tweet at me claiming it, DM me your PayPal info, and I'll send you your money (limit of 5 people per missed post). I'm going by Eastern Standard Time (NYC time).

To find out why I'm doing this, check out the first section of the first post.

Post Number	Date	Topics
0	Nov 27, 2018	Why I'm doing this, setting up environment, basic syntax
1	Nov 28, 2018	Learned more about lists and functions, building a simple database app
2	Nov 29, 2018	Some Lisp history, syntax, and semantics
3	Nov 30, 2018	Wrote a tip calculator
4	Dec 1, 2018	Edited tip calc to use local variables and briefly touched on other things I learned
5	Dec 2, 2018	Finished Chapter 4 of PCL, talked about editor choice, and reflected on the concept of code as data.
6	Dec 3, 2018	Got a better grasp on when and why you'd use macros and learned more about Lisp functions
7	Dec 4, 2018	Finished Chapter 5 of PCL. Got more in-depth with functions
8	Dec 5, 2018	Learned more about variables and closures
9	Dec 6, 2018	Updated my Tip Calculator program and finished the chapter on variables
10	Dec 7, 2018	Day 1 (part a) of Advent of Code 2018. Code full of bad practices, but it'll have to suffice for today.
11	Dec 8, 2018	Made day 1 (part a) of Advent of Code nicer and mostly did part b although it's not fully functional yet.
12	Dec 9, 2018	Tried to figure out what's wrong with my AoC puzzle 1(b) code. Made some progress but now I'm getting a new error.
13	Dec 10, 2018	Worked on 1b of AoC and began 2a. Still doesn't work.
14	Dec 11, 2018	Didn't code today, instead read about how many of the common control-constructs are, themselves, macros written in CL
15	Dec 12, 2018	Wrote a simple journalling program.
16	Dec 13, 2018	N/A: I didn't do it
17	Dec 14, 2018	Attempted to modify my journal program to save the path to the journal entry so the user doesn't have to repeatedly enter it. It half-worked.
18	Dec 15, 2018	Learned more about how lists work in CL. They're basically just linked lists of "cons cells."
19	Dec 16, 2018	N/A: I didn't do it
20	Dec 17, 2018	N/A: I didn't do it
21	Dec 18, 2018	N/A: I didn't do it
22	Dec 19, 2018	Learned about how trees are structured in CL. Cons cells all the way down.
23	Dec 20, 2018	Learned about sets in CL and some operations you can perform on them.