I had the pleasure at serving at the Basilica for a spell before powers-that-be decided that adult servers at Sunday mass at our parish was inappropriate.

My experience and reflections mirror your own (the comment on the paten made me chuckle with familiarity), and “seedbed for vocations” seemed a particularly apt metaphor. Altar serving is a great place to “scatter seeds” in order to see who will take root, thus a role well suited to clarifying as well as planting vocations. I found serving to be quite rewarding, and I was glad to help our head altar server when he was short on bodies to aid at the altar, but I realized while there I don’t have a particular calling to be regularly in the sanctuary (this is reflecting on my consideration of the diaconate). I’m most at peace when in the pews (especially when with Jessica and Benedict) adding my personal prayers to those of the liturgical assembly, and thus (along with other considerations) my vocation as unordained seems fairly certain.

I imagine that to be true of any number of men (young and adult); honored to serve, but unless they feel themselves taking root in the sanctuary, they’re probably not going to leap into seminary. If, however, like a magnet the closer you get to the altar the stronger you feel its pull, that — if confirmed by other markers— seems like a good sign for a call to ordination. So we need to get all young men in the sanctuary as soon as sacramentally and maturely appropriate, in order that they may evaluate that magnetic draw and the possibility of taking root there… for if they don’t get close enough, they may never know for sure.