Texan traveling to Washington (the state), confused about reason for lack of reciprocity.

So I already know that my Texas LTC is not reciprocated by Washington state, but the reason they have listed on the attorney general's website is what I'm confused about: http://ift.tt/2hiMBDk says that Texas allows persons under 21 years-of-age to have a license, but I'm unaware of this. Is there an exception I don't know about or something? I once heard someone (of no authority) say active duty could get one at 18 but I never saw any official mention of it. via /r/CCW http://ift.tt/2httPr9