What is self control?
The restraint of action toward a particular desire {A}.

But why?
Because that desire is in conflict with a stronger love {B}, and acting on desire A would hinder the fulfillment of the more highly valued B.
Let's say one desires to eat nothing but cookies, and also desires to be relatively healthy. If the desire to be healthy is greater, one will be able to refrain from subsisting entirely on cookies.

St. Augustine defines sin, therefore, as disordered love. If one loves/desires anything more than God, one will naturally place other things above pleasing God and following his commands when there is a conflict of desires.

ref: Tim Keller

Good Reception

The LORD will hear when I call to him. —Psalm 4

Answer me when I call to you,
O my righteous God.
Give me relief from my distress;
be merciful to me and hear my prayer.

How long, O men, will you turn my glory into shame?
How long will you love delusions and seek false gods?

Know that the LORD has set apart the godly for himself;
the LORD will hear when I call to him.

In your anger do not sin;
when you are on your beds,
search your hearts and be silent.

Offer right sacrifices
and trust in the LORD.

Many are asking, "Who can show us any good?"
Let the light of your face shine upon us, O LORD.

You have filled my heart with greater joy
than when their grain and new wine abound.

I will lie down and sleep in peace,
for you alone, O LORD,
make me dwell in safety.

—Psalm 4