About 5 years ago, a co-worker of about 3-4 years looked me dead in the eye one day and said “Your the only person I know that is fueled by anger”. I did not respond as I found it such an interesting comment from someone that hardly knew me and only during work hours.

About 2 months ago, another co-worker told me that after working with me for about 4 years he could safely say that my fuel had been upgraded, he commented that I was clearly fueled by;
Anger
Bitterness
Loneliness
Caffeine
He said that at any point in any day at any time of the year, you could safely pick any three.

Honestly, at this point I was just disappointed I could not pick all four.