I fast every Wednesday. I don't eat until 8 pm.

Some Wednesdays, my energy is high and I'm just breezing through work. Since there's no food or drink break, I start working in the morning and I don't leave my desk until I'm going for prayers by 4 pm.

Some Wednesdays, I wake up not wanting to do anything. Super lazy. Just wanting to sleep or scroll the phone. Today was one of such Wednesdays. 

I really can't place the reason for inconsistency yet.