What is second nature?

Is it like first nature, once-removed? I understand it to be those things that come naturally. There are certain things that are second nature to me:

Horses: brushing, saddling, mounting, riding-both of us feeling the wind and sun or rain and cold, warm breath from a soft muzzle on my arm, moments where I feel part horse, jeans and boots.

Loving: grey, rainy days, voices singing harmony, the touch of tight embrace, joy on another’s face, hitting the target-

falling in love with each new experience and throwing myself into it with little, sometimes no, restraint.

Writing: poems, stories, memories-

all the fleeting moments that whip through my head, some end up on paper and others continue their plots tucked into the notebook filed in my thoughts.

What is not second nature? Does that make it third or fourth nature? Nature you have to practice? Non-nature? Anti-nature? There are certain things that are not second nature to me:

Chopping onions or grilling, unless you enjoy meat cooked to the toughness of a piece of wood.

Playing games in relationships, I can never catch on to the rules.

Sounding intelligent on the spot, “uh, er, um, gee.”

Walking in high heels and a dress, see above “horses.”

Computers and staying up late, especially not together.

Ignoring someone’s pain and keeping emotions hidden;

Look before you leap and guarding my heart.

Riding a bike, did you know they can buck you off?

Holding back and lack of appreciation, or-ignoring beauty

Have you seen the jagged edge of Saw Tooth?