It's like trying to hook up with an old significant other and realizing that while the nostalgia is strong and sweet, you aren't really compatible people anymore. Sure with some effort it can be made to work but it's never really comfortable, not like it used to be. The intervening time has wrought too many changes.

What's worse, as you explore the old relationship with the perspective of an older and more enlightened self you start to realize that the old relatoinship was flawed, was codependent. It only worked because the significant other demanded and got 100% of your attention. There was no flexibility, no breaks, it took endurance and an exclusion of all other interests to reap the rewards.

That's how I feel now when I sit down to a console or PC game.