<human>: Can you succinctly summarize the text in 1-3 sentences?

My girlfriend has a sexual past that includes a large number of sexual partners with people that she either was not in a relationship with.  For some reason, I see this as a concern.  The part that makes me think and know this is unreasonable is due to the fact that she has been a faithful and committed girlfriend thus far to me.  However, I seem to attribute her past to commitment issues, general promiscuity, and someone who may enjoy casual sex [I'm someone who isn't fond of that - I enjoy having sex with people while I'm in a committed relationship].

Prior to this relationship, I've had sex with only one other person while I was in a 3.5 year relationship with a girl who had only had sex with a long term boy friend prior to me.

Seeing as she treats me well and I don't want to let this get in the way between us, what can I do to be rational about this?  I'm in very intense schooling and I feel like the stress from that is allowing me to be irrational about this.  Why did she have one night stands?  Why did she hook up with scumbags?  Does this mean that she will get bored with me?  I'm obviously insecure, but I need some help.  I love this girl and I want to be the boy friend she deserves.

She has contracted herpes along the way from these encounters as well.  We are sexually active and are practicing safe sex if this is relevant.
<bot>: Girlfriend has a long sexual past, I do not.  I'm insecure and want to know why this bothers me.