I found a Chinese counterpart to the English saying "You can't teach an old dog new tricks" and I like it better.
It is: 活到老学到老 (huo2 dao4 lao3, xue2 dao4 lao3*) "One is never too old to learn".
It is much more positive and very true. We should continue to learn new things throughout our lives.
*The numbers after the words refer to tone marks