Over the year's I've been like that, and as I started experimenting with different video games I determined what really draws me in.
RTS, TBS, 4X, and W/J/Sandbox RPG's are really the only games I play these days.
Pretty much every other genre bores me to death. Especially FPS. One of the only exceptions being Half Life 2/Portal 2.
Now I just stick to the genre's that interest me and gaming is great. The majority of games that get hyped, and the majority of "AAA" games I can never finish. I get bored half way through, or even after a few minutes. Where something like Sins of a Solar Empire, Civilization V, Europa Universalis IV, Skyrim, Starcraft 2, etc. have sunk in over 100 hours each.
Similar situation. I'm turning 30 and I have had this happen to me several times over the years. I've been playing since I was 3 years old. I usually just don't play for a few months then come back to it and im excited all over again.
Also it usually takes a special game to get me going again. last time it was Kerbal Space Program.
You need to try different genres. Most of the people who run around moaning about how they are "bored of" videogames are just sick of online FPS deathmatches. Here's a hint: Those only became the dominant genre over the last 7 years. And I can't believe more people don't get sick of them.