The year you leave your home continuum doesn't necessarily correspond with the year you arrive in HQ. For example, Nume left the Real World in the late seventies and arrived in HQ approximately two decades later without living the intervening years. Something similar could have happened to Makes-Things, since he appeared shortly before the Cascade happened in the mid-eighties.

~Neshomeh

As Laburnum says, it's a passage of time thing. People do celebrate birthdays, but they never really seem to get that much older ... You're as old as you think you are, I suspect, which means that the scatterbrained or distracted people are much more likely to hang on to youth perpetual :)

If he ignored it sufficiently, and he strikes me as the type to not notice the passage of time under normal circumstances, he may not have aged at a normal rate.