Out on a school night

I'm not a gal who goes out on school nights often. Let's face it. I'm almost 40. Those days have mostly passed me by.
But, I broke from my usual mantra (you must be in bed by 11. you must be in bed by 11) and ventured out after work last night for a show in Charlotte. I checked out the Saving Able and Hinder concert.
At times it was obvious to me why I don't go to such events anymore. I felt like an old woman amongst teens and 20-somethings. But then I'd see a gray-haired man or a wrinkled woman and feel a little less like a hag.
So the show was good, though really crowded.

Then came the morning. I woke up on this icy morn, fatigued and with a slight headache. I wanted nothing more than to snuggle up in the blankets and hide until at least 11 a.m. But alas, I am an adult and do not have such luxuries. (Perhaps one day I'll hit on a lottery ticket and this will change.)
The ride in wasn't really treacherous from the rain and ice, but there's certainly a motivation issue this morning. I've finished off one story and conducted a phone interview but with a sluggishness I could avoid in my younger years.
If this is the feeling post-40, what will life be like in the next decade? Should I invest in a heating blanket and more movie channels since I clearly don't belong out on a school night?