Well, as rare as this might be - it is probably greatly psychological. If you had pocket Tens and they had pocket Aces instead of pocket Kings, then you'd probably question the odds in the same. The accurate way to get an answer is actually "what are the odds of your range (or exact holding) against their likely range of possible hands."
Luckily, this is a math question a poker calculator can come up with
With the answer I'll give, I'll go off of this range I made up for this spot, but naturally you can adjust this to re-calculate yourself if you had more information on what hands (or type of hands) they might play.
Since Villain only has 8 Big Blinds, they might be shoving with a wider range than I'll give, but for simplicity sake I'll say they are shoving All-In with 350 hand combinations of the possible 1326. This is 26.40% of all hands they are continuing with and folding the rest.
A range like that might look like this:
22+,A2s+,K9s+,QTs+,JTs,T9s,A2o+,KTo+,QJo
Again, we can adjust this range (them continuing with these exact hands might or might not be best, but it is just a sample here). For example, this range has them shoving every pocket pair, but TAG players might not always call off your 23BBs when you cover their stack and they have Pocket Deuces (22). Similarly, this constructed range is shoving "any Ace."
Given this range against exactly pocket Tens (TdTh I used but suits don't matter for the math here), then your hand is estimated to win 63.63% of the time and Villains range will win about 36.37% of the time.
As the math indicates, your Tens are good just under two-thirds of the time. It really isn't as unlikely you were beat as you were. Variance in poker is very real, but over the long-haul, your play was "+EV" and you'll come out better.
For this calculation, I used the free poker calculator Equilab, but other poker calculators exist out there to calculate the same.
