Do you have money to stay a year off work? If yes, quit your job and work on something yourself (you sound like you could figure out what it is). Reclaiming those 8 most creative hours of your life can make a huge difference. Even if you don't have an absolute business plan right now, having an open horizon will give you a new perspective.

I took a year off at 28 after 7 years in a small company to do a Master's programme. I ended up becoming an indie developer and its only gotten better since. We live in great times, take advantage of it. If, OTOH, your plan is to start a family etc., it would be better to stick to the corporate safety.

But most of all, you should not take other people's advice too literally; life doesn't come with a manual, and nothing can guarantee happiness.