Is it normal to be nervous around security guards?

I'm not afraid of the police, nor am I afraid of security in general, but sometimes when I am checked or go through a security check point I tend to be a little frantic. For example, I work in a government building and I do have a security clearance/badge, but this morning I had to escort someone in, and I signed them in. But I quickly signed them in without going by each line and signing my name. The guard corrected me and I signed again. But I guess I was a bit frantic, not as in afraid but not exactly normal. Is this normal to be a little off kilt around security guards?