Is it normal to like showing off my newly acquired muscle?

I don't do it all the time, just during rare, opportune times. I wear long sleeved hoodies at work and hide my skin all day. Most of the people at work don't know what my body really looks like.

When my co-worker said she wanted to fight me because I couldn't give her a ride home, I took off my red hoodie and didn't back down. She backed off right away. I got compliments on my triceps from other people.

Then that time when one of the managers wanted to make the work meeting more interesting and had people do pushups. I took off my red hoodie and did twenty. I was quite proud of doing the amount I did.

Then yesterday when someone called me over to pick up case packs of water for a manager. The second she saw me she looked disappointed and said she was hoping for a big strong male worker. I rolled my eyes, took off the hoodie, and lifted the packs. She actually apologized to me and said I looked strong.

I'm going to refrain from showing off for a while. It's kind of fun hiding this secret from people.

I'm proud of all the work I've been putting into myself. Is it normal?