I'm a new Nurse, but also one of the "over 40 gang"...

After 3 months, I'm finally getting used to 12 hour shifts (although the last 4 hours seem to drag on forever). I'm on the floor by 6:30am and never leave until at least 7:30pm, so it's more like a 13 hour shift. I'm ok until I get home, then the exhaustion hits. We have 3 Sons - 2 of them school-age, so the days I work, really hard to find the energy to help with homework or anything else for that matter. Floor Nursing is hard, so I'd be just as tired after an 8 hours shift.
The drawback - if you have to do a few 12's in a row - there is very little time in between to do much more than eat and sleep before you have to be back at work. On the plus side - you get 4 days off a week. I hate getting up before 5am, so it's nice only having to do that 3 days a week.
Like AuntieRN said - what's 4 more hours for 3 shifts, if it means you get 2 extra days off a week.... I use one of those 4 days off when the kids are in school to recharge my battery on the couch with my friends Oprah, Phil and any other mindless TV shows I can find....