Only some kids truly have an aptitude for mathematics anyway.That's an absurdly strong and inaccurate statement that feeds into psychological walls that then get erected in the minds of the young and perpetuate ad infinitum. The psychological research here is very clear: stressing work, over some sort of ethereal innate 'talent', in ANY area makes a massive difference in skill attainment.
I don't have time this moment to get into this in any depth, and, it depends, of course, what specifically you mean by "truly have an aptitude", but, too many people have a view of math, in particular, as some kind of magical realm only "truly accessible" to a few. There's a lot that goes into forming the basis for skill in any domain - quite a lot of that likely reflects all sorts of extremely early life parameters and events prior, even, to acquisition of language. The "playing field" is never "level" in any pursuit. But, based on my own experiences and knowledge, there's a mysticism or whatever surrounding some subjects that's just bizarre, IMO.
I would personally, in light of what I've seen to date, draw a very direct analogy with the formation of an NBA player (as an example). Someone can start playing very young, become incredibly adept, and easily never get to the height, strength, etc. (typically) required to make it to NBA level. Nevertheless, these people go on to be trainers, coaches, announcers, etc. This is even more relevant in fields that aren't in the "tournament career" realm.
Often, what holds people back the most, is substantially unfounded statements like yours.
Here's a jumping off point for further info (not enough time to provide more complete refs, currently, apologies): https://www.psychologytoday.com/us/blog/the-procrastination-...