It's harder to learn chess later in life because as you age your raw thinking power diminishes slowly over time. Your brain just simply doesn't work as well as it did when you where 20. As you start using your mind more with daily chess training some of what you lost with age might come back a little, but it will never be at full capacity :(.
A lot about chess has to do with learning the right habits, and becoming aquainted with basic tactical motifs and mating nets, and later move on from there.
For example my problem is that I don't consider other possible moves. I just merely make the first move that comes to my mind sometimes and lose a lot of games stupidly because of this. A bad habit I learned from playing only blitz.
I have lost so many games ,Iam beginning to hate this sport