[aleph_minus_one]

> Sadly, I feel like SR can only really be "understood" as a complete theory. All the individual phenomena (time dilation, length contraction, relativity of simultaneity, constant speed of light etc.) are very hard to understand, because you cannot just take one of them and add it to classical relativity without immediately running into paradoxes.

This is because you implicily used the (wrong) postulate that "phenomena of special relativity can be iteratively added to a a lassical description of a non-relativistic theory".