[drangundsturm]

His example is a little flawed there at the end. If he is correct then a 50 year old should experience time flying by at ten times the speed of a 5 year old. I really doubt it is that much of a difference.

The apparent "speed up" effect is perhaps a combination of things, but testing has shown that as we age our brains literally slow down. All that information stored up there makes it take a little longer to make a computation. Also there are physiological reasons why processing time lengthens. This probably explains most of this perceived "speed up" effect. If your brain is taking longer to compute things, the outside world seems to whiz by faster.

[BipolarBob]

"So time must be “linear”, that is, it is not accelerating."

Not an entirely true statement. Time is relative (see Einstein).