Not showing Levels in Creative

When using commandblocks to make some XP givers, I was testing them and realized I could not see my levels when in Creative Mode. I tried using it in the command line and nothing happened. I recieved experience but I never got levels.

What I expected to happen was...:
I thought I could see my levels so I know how much XP it takes for a level

What actually happened was...:
I got the XP but I never gained levels, even when giving myself 4000+ XP

Steps to Reproduce:
1. Go in Creative Mode
2. Try to give yourself XP
3. You won't gain any levels no matter how high the number