Yeah I know what you mean, I also looked for comfort in numbers many times.
I thought Blizzard normalized mount drops to be all at 1% (except personal loot mounts)? So cheer up.
So just a few numbers based on
1% dropchance:
If you get your mount before attempt
69 you belong the the lucky people, because until attempt
69 the chance of
not getting the mount is higher than getting it.
Starting with attempt
69 the tide changes though, which means the chance of getting the mount at least once in
69+ attempts is higher than
not getting it.
An interesting number is attempt
100. Many people assume that with
1% dropchance you should get one mount in
100 attempts, but this is just the normal distribution, and not the probability. In fact the chance of
not getting the mount in
100 attempts is
36.6%.
Another noticable mark is attempt
458. The chance of
not getting the mount in
458 attempts is
1%, exactly the same as getting the mount on the first. So if you pass this mark, you really can call yourself unlucky.
And the final statistically significant mark ("statistically impossible" = starting probability squared) hits at attempt
917, when the chance of
not getting the mount reaches
0.01%. If you should pass this mark, the probability that someone at Blizzard is watching you and prevents the mount from dropping for you is higher than not