When can I stop?

When can I stop?
That's the question I want to ask.
When can I stop working out? At what age is it ok to not workout all the time? I really want to know.
When I was a teenager I thought I would work out till I was 30 then just coast in middle-agedness (is that a word?). When I told my husband this in my early thirties, he just laughed at me like I was crazy. He was right. And so are all my friends at the gym. When I asked them this today, they reminded me that as I get older my metabolism will slow down and I'll have to work out more, eat better, and I will also feel worse (sore muscles, aches, pains, and all).
They are right (although I don't claim the sore body part), but they are right, our bodies are built to typically change with age and that means if we are trying to maintain something we will have to work harder at it as we age.
This news stinks!
I don't like it.
I want to stop... yea, right! On the one hand I would love to stop. Meaning, more time to do other things. But on the realistic hand I know that if I stop... I will gain weight and keep gaining weight, just like I did after high school. I was 120 in school. I peaked the scale at 150 my freshman year of college (hey, I thought it was only supposed to be the 'freshman 15' ???!!!), which then caught my attention and I brought it down, and up, and down (notice the yo-yo pattern beginning here), till I got married at 128. Then I was basically 130,135,140,145,150,155 over the next several years. See what happens. When I don't work out consistently and regularily I gain a pound at a time till about every 12-18 months I've gained 5 pounds. I can't keep going at this pace the rest of my life, so I've GOT to workout. But I seriously want to know when do I EVER get to stop? Because, deep down, I really wouldn't mind stopping. If for nothing else, just to get that time back to do other things.
Maybe this isn't the kind of post fitness fanatics want to read. You probably just want gung-ho, super-motivational stuff to keep YOU going. Problem is... right now I'm having a hard time just keeping ME going.

Maybe I just need something new. (No Jen, I don't want to press 'play'. But who knows, maybe I should. I guess it would be something NEW. Honestly though , its just hard for me to get motivated to do different at-home routines than the ones I already know from my collection).
I'm loving riding my bike, but I know its not enough of a workout to do much for me. At least not in comparison to running or classes or weights. So even though it may be fun, its actually too easy to count as exercise for me in my book. Maybe I want new classes at the gym, maybe I should try some, or use my free pass at my husband's gym and do classes there. I don't know, I just need something, because I'm just not 'feeling the love' for my workouts lately, if you know what I mean. Don't get me wrong, I love my teachers, and my gym friends. Its just me. On the inside, some switch has gotten turned and I'm having a real hard time getting it switched back. Then I think of people I know who never work out and look perfectly fine and I get mad (and ok, a little jealous) that they don't have to spend time working out, yet they look great and are in good health. Wrong, probably. But I'm being honest here. Or maybe I'm just whining, I don't know. But since I'm probably not really accomplishing anything with this post I'm going to end it. Comment for me if you have any ideas on how to change this mindset I'm in right now or any other helpful ideas for anything! thanks :)