Can we understand God, even a little?

We keep all mitzvot and shun all prohibitions because that's what G-d wants. After that we can spend a lifetime trying to understand better.

Phil Chernofsky,

Hebrew-Spanish prayer book
Hebrew-Spanish prayer book

Why are we commanded to dwell in a sukkah for the seven days of Sukkot?

So that all generations shall know that G-d protected us during the sojourn in the Midbar (with actual booths and/or the protective heavenly clouds) after He took us out of Egypt.
How do we know that this is the reason?

The Torah tells us in the pasuk that follows BASUKOT TEISH'VU SHIV'AT YAMIM.

In this week's sedra, Ki Teitzei, the Torah showers us with 74 mitzvot - the most of any sedra and 11 more than the #2 sedra, Emor.

Among them we find the prohibition of muzzling an animal when it is working with food (that it would like to eat - not necessarily our kind of food). Why prohibit this? It would be cruel to the animal to do so.
Nice answer, but who says so? The Torah does not give a reason. Our Sages state that this mitzva is one of several that are the foundation of the whole concept of avoiding cruelty to animals.

Those same Sages (some of them) attach a caveat warning us second-guessing HaShem. They opine that we need to hesitate giving reasons with our finite (limited) logic to the commands of G-d (that do not have their reasons spelled out for us.

With that warning, however, they do attempt to explain many of the mitzvot. Basically, the warning is not to assume that we totally understand a particular mitzva, at the same time that we strive to understand what and why G-d has command something.

Sometimes, Chazal are 99% confident that the reason(s) they give are correct. But there is always (or should be) a prime reason for a mitzva - namely, that it is a Decree of the King. Then other reasons can (and should follow).

Take a look at another prohibition in Ki Teitzei - that of harnessing an ox and a donkey together for plowing. Chazal teach us that the Torah Law includes the harnessing of any two non-compatible animals for any purpose. This includes the two giraffes harnessed together with an elephant pulling a band wagon and trailer with an old man on the porch sitting on a rocker, that can be seen and read about in Dr. Seuss's And to think that I saw it on Mulberry Street. That too is ASUR MIN HATORAH.

This mitzva is also explained as an act of cruelty to animals to be avoided. But there is a wrinkle to this mitzva. Rambam is his name (actually, his acronym). The Rambam says that the Torah prohibition of LO TACHAROSH applies when one animal is kosher and the other is non-kosher. Ox and donkey is a Torah level violation, but elephant and horse is 'only' a Rabbinic prohibition. According to Rambam, there is something else to this mitzva. Not so simple.

And what about SHILU'ACH HAKEN, also from this sedra? For several reasons one cannot simply chalk up this mitzva to avoiding TZAAR BAALEI CHAYIM. In fact, it might be the opposite. Certainly, not simple to understand.

There are CHUKIM whose logic and reasons escape us. There are Mishpatim that lend themselves to easy explanations. There are many mitzvot between these extremes.
Bottom line: We keep all mitzvot and shun all prohibitions because that's what G-d wants. After that - and only after that - we can spend a lifetime trying to understand G-d, the Torah, and the Mitzvot better and better and better.