These plants can get quite old - so 20 was middle age compared to some that I know of. When I was still working, a co-workers mother had one that was 35 - don't know if it's still around 6 years later, or not.

Before this one that just bit the dust, I had another very big one that was about 15, and in the course of moving and letting a former relative plant sit it for a month, she killed that one for me by watering it daily after I gave her specific instructions on how to care for it. I was furious!!!!