What is the right age for Disneyland?

I feel like I hear people all to often saying 'we are going to wait until the kids can remember' to take their kids to Disneyland.  To hit the free under 3 years of age limit, we took our kids a few weeks before their 3rd birthday.  It is now a month later and the triplets still talk about mickey mouse land and it is one of their favorite topics to play around.  Yesterday they built Disneyland, they put their FP castle & pirate ship and many other memories from their trip into their mickey mouse land.  They even took had a doll house 'hotel' nearby their park.  Sure, going as a teenager to Disneyland for the first time has its memories but I did not fill my days after running around on the playground or in my room talking and reliving my time spent at Disneyland.  Now I ask you - what is the right age? Is it worth the parents money for their child to remember it or to play and live the excitement from their day Disney regularly?  For me personally it just makes me smile to see how much my kids truly enjoyed their day at Disneyland by hearing them talk about it and reliving it, it was worth every penny and every minute.