"I was just wondering if any of you find it easy seeing other aircraft close by or not and have you ever though "pheeeew, where did he come from...." "
No, and yes, all the time
To be fair however, consider driving the same distance. You will pass thousands of other cars, on a reciprocal heading, within a few feet of you, at closing speeds of the same order of magnitude, and you will be subject to the less than favourable statistics for several times as long.