I'm a morning person. I wake up early, I do my best work early, I can concentrate better early, and I love to do all this before any of you wake up. That's just me.
Some people are night owls and the thought of going to bed before midnight is dreadful to them. We all have different patterns, and we all have different "peak hours" in which we do our best work. Mine are in the morning, yours might be at 4PM, that's for you to know and me to try and disrupt with my next few sentences.
When we fall into routines, we become complacent. I found that shocking my system and changing up habits are great creativity boosting tips.