40 Years old

I am now 40 years old.  I now know that it is time to start working out.  I have yet to follow an exercise schedule which has been quite embarrassing for me.  Thankfully, I managed to lose weight despite the lack of said exercise.  I heard that the older one one gets, it will be harder to lose weight. If this is true, then I will be a 40 Year old PCOS sufferer who will have an even harder time losing weight.  What was I (not) thinking?