Where's the balance?

It's almost 10:00 pm and I finally have the chance to get to emails and do some research to help me with work tomorrow. As I sit here, I wonder, where is this balance I keep hearing so many "experts" write about. No working mother I know feels they have a good balance in their life. I know I don't. My entire career I pushed the envelope, kept my skills up to date and tried to remain in the front of the pack. I thought when my son came along that nothing about work would change. Guess what? Everything changed. I spent years working the "extended" hours to prove myself and gain the respect of colleagues and those in the positions I strived for, only to feel guilty now that I am a nine to fiver. Why should I feel guilty? Why should I care if the fellow in the next cube looks at his watch as I walk past at 5:15. Was I supposed to assume when I took my job that 9-5 actually meant 8:30-6:00? We are so busy working ourselves to death that we forget about what really matters in life. Cause let me tell you... I am not retiring any younger than my grandparents and I work a lot more hours. So if working moms are made to feel guilty FOR working, and still feel guilty for not working overtime... where's the balance?