Why do I always get more sick than my kids?

My daughter was sick last week with an ear infection. I got sick from that. Well, I have been down and out all weekend. I went to the doctor today. Bronchitis, sinus infection, cold, and maybe pneumonia. I am on antibiotics for pneumonia now. I keep thinking I am going to cough up a lung. Too much info, huh? My fever won't leave me and my body aches like I am 80 instead of 44. Getting older does have its disadvantages.