I don't like this argument, it has a singularly at age zero.
The visualisation sidesteps the problem by starting at year one. You can also add arbitrary constants or other tweaks, but then the idea lose its elegance and you can make it say anything you want.
My recalled experiences approaching age zero closely resemble an asymptote. I can accept that the subjective time between 0.0 seconds (when is time zero, anyway?) and 0.1 seconds was infinitely longer than the last 40 years. Recall of things since I was five only gets moderately difficult, while recall of experiences from one year old or earlier is almost completely inaccessible.
One could say that's because I lacked the experience to interpret and store my sensations at the time, and that those were gradually gained, but to my view that's not a refutation but actually reenforcement of the argument. I'm still learning higher level abstractions every day; the tools to more efficiently store sensation are gathered as new sensations are gathered.
When I was 14, every day at work was radically different than the last. At 44, they're pretty much the same. When I was 14, 8 hours was like forever. These days, if you asked me at 9PM, there might be a 2-3 second delay for me to remember if I worked at all that day.
The visualisation sidesteps the problem by starting at year one. You can also add arbitrary constants or other tweaks, but then the idea lose its elegance and you can make it say anything you want.