Dead battery

It doesn't happen very often  I was kind of embarrassed but at least I was prepared. I had left my headlights on at work and by the time I noticed them  they were really dim and it was six hours later. I shut the headlights off but there wasn't enough power to start  my car. I called my husband and he reminded me that in the trunk was a booster power pack for just such an occasion. So I opened the hood followed the instructions and the car started right up. My co-worker guys were asking me if I needed help and I just looked and smiled and said no. I have it under control. Thank you.