Some change the routine every week.
Some change it everyday, some every month...etc.
It depends on your goals and time frame. You will have the hardest goal if you want to look ripped like some who are found on this board. Being able to show your abs is not easy, diet has to be watched like a hawk watches his pray. Suffice it to say that any improvement you make to your health is worth twice the effort you put in.
And, well, a geek wants to look ripped to feel better. So it goes both ways man.
You gotta be doing this for the right reasons too.
I don't know how much you weigh, but I have to say, no, it won't take you years to lose the weight you want to lose. With proper knowledge and effort you can lose a decent 10 pounds per month.
If someone says they go 3x a week, that's what it means, there previous routine could be completely different.
Hope this helped.