Nope, I did think for a while that my own age (31) is the problem, but since then I have replayed through great games like Fallout 2 again and found new great games like Kings Bounty and Fantasy Wars, discovered old classics like Master of Magic for myself. Now I can safely say you can still enjoy games like when you were 15 and its just the new games that do in fact mostly suck, probably due to their 99% graphics budget.
I can't tell you how good I felt during the last playthrough of Fallout 2, I was simply satifsfied, warm and fuzzy, even happy days after I played it.