very old guys (60+), with no prior flight time often take quite a bit longer as their reactions just aren't as quick.
Who you calling "very old?" Really depends on the individual. Sixty is the new forty. I started training in helicopters in early 2007 at age 64 in a 480B and had PPL within 6 months, then I-H and CPL-H, and now finishing up CFI-H at 68 in my own B407. Along the way soloed in R22 and R44. My principal instructor, a very seasoned guy with 20K+ hours, tells me I fly better than many he has worked with. He calls
me with questions on advanced avionics. However, I have been flying fixed wing since age 23. The Designated Examiner I take my checkrides with is 70+. Hoping to be flying safely at 80; we'll see. I do take flying quite seriously, do a lot of recurrent training, and have a strong safety mindset, all of which helps.