I don't think people inspect time enough for them to become disturbed by it.
This is probably a good example of "ignorance is bliss". I can't conceptualize your experiences at all.
I have considered that, and it's part of the reason. If everyone had an IQ of 120 and studied stuff and contemplated stuff I'd probably be fairly comon, thou far from universal.
Now start contemplating moving SIDEWAYS in time.
String Theory, I think it is, has time as taking up another 3 dimensions. Time with an X, Y, and Z axis. NOW tell me it doesn't scare you, if only because you cannot possibly imagine what that means.
I'm pretty sure you have gotten string theory and physics in general wrong in ~15 ways there.
I dont find imagining multiple time dimensions very hard at all, atleast not harder than imagining the single one here. In fact, I find such a setup would be much less unsetteling and confining than the linear time we corently have.
As how to imagine it, there are probably a few ways, if you have a simple low amount of timelines interconecting like in time travel stories, it is to trivial to spend time discusing here. If, on the other hand, you imagine a smoothly truly 2d time, a good trick to imagine thinking in a world like that is to imagine the neural net that is you brain like the simplified computer versions that are curently avible, going iteration by iterationg. Then you make it brach into two timestrams, identical exept that each neuron knows wich one it is in. if you do these branchings often, in fact evry iteration, you now have a sturcture that has abaut the same resolution in both time dimentions (note that technicaly the second one might not count as time yet actualy, but it will become a time dimention soon so lets just call it that).
A small tree like this, downwards is the "normal" time dimention, sideways is the second one.
n
/ \
n n
/| |\
n n n n
Each neurons state in iteration N is dependant on the states of the other neurons in the previus iteration - it's parent node in the tree - in this setup. You still have no experience thou, as each of the neural nets are in separate timestreams.
now, however, you give more information: in adition to basing the state of each neuron on the state of the other neurons in it's parent, you also base it on the states of neurons in the nighbour timestreams of the parent, transforming the stucture from tree-like to cloth-like.
a cloth structure, downwards is the "normal" time dimention, sideways is the second one.
n
/ \
n n
/ \ / \
n n n
/ \ / \ / \
n n n n
/ \ / \ / \ / \
n n n n n
As you can see, each node here is based on two parent nodes, and information can travel at a "speed" of a maximum of one sideways step for each downwards iteration. This would most likely "feel" like living in two time dimentions, althou I'm not sure if it technicaly counts as such. This Is the last version show here that I know is computable.
a cloth structure, downwards is the "normal" time dimention, sideways is the second one.
n
/ \
N N
/ \ / \
n @ n
/ \ / \ / \
N n n N
/ \ / \ / \ / \
n n n n n
here is a slightly diferent configuration again, the state of the @ is dependant upon the capital Ns, it basicaly works similar to relativity in that while information travels "backwards" in time, the finit speed at wich it can move throught other means is slow enought that it shuldnt be able to form paradoxes, and as such this *might* be computable.
a cloth structure, downwards is the "normal" time dimention, sideways is the second one.
n
/ \
N N
/ \ / \
n @ n
/ \ / \ / \
n N N n
/ \ / \ / \ / \
n n n n n
This is the last example, this is completly 2d and symetric in time, however I cant figure out a way it could posibly be computable or even what it would feel like.
That wasnt so hard was it?