It's a simple question really. Assuming you EVER really "liked" working in IT, or even if not in a formal IT environment, that you ever liked working with computers and related "technology". Do you still? On average (not just today or yesterday), do you still enjoy working in the field of technology as much now as you ever did in the past?
Me? Not so much.
Why? In the 1990's, the party-time of IT, things were driven by the technology itself. The features, the capabilities, the new places to explore and improve upon, those were everywhere. It was almost a free-for-all as far as finding problems and working out solutions with the tools at hand. It felt like building a house or rebuilding an old car. It was yours to conquer.
Today, it's mostly about cost cutting. The projects aren't really driven by IT people anymore either. They're being driven by bean-counters. People in suits, with MBA's and PMP certifications. People who can spew ITIL, SOX, SOA, and SDLC mantra all day, but can't write a single line of code or install a software product of any real meaning (server-based is what I'm talking about).
In the late 90's and early 2000's, if you asked most IT SysAdmins "is this product/technology something YOU would have chosen?" they would have said "Yes. I chose it." Today, most that I have talked with say "No. It was chosen by someone else and I don't like it.". Many feel that the technology they are supporting is outdated or inefficient, but they don't have the authority or backing to pursue an alternative. Even when a proof of concept shows enough promise towards saving time and effort, most SysAdmins don't have time (or sufficient skill) at presenting an MBA-oriented business case to get it over the hump. To us, the features save time, do more, and free us to do other things. To the financial departments it's only a matter of how much it will cost to implement (including training and support), and what will it provide in savings and over how long. The old ROI issue. However, today it's less about the "R" (return) and more about the up-front cost.
Do you still go into work (or work from home) on weekends or late weeknights? Is it by your own choosing because you LIKE what you're doing? Or is it because you HAVE to do it? Or do you even work into your personal hours? Are you as driven by the fascination of what you're working with now as you were five or ten years ago? Or are you driven more by staying employed and getting a paycheck? If you could choose the technologies you work with, would they be the same as you are already using?