There is no documented evidence to suggest that Albert Einstein ever disliked his own theory of special relativity. In fact, Einstein's theory of special relativity, published in 1905, revolutionized our understanding of space, time, and the relationship between matter and energy. It introduced concepts such as the constancy of the speed of light, time dilation, and length contraction.
Einstein's theory of special relativity was initially met with skepticism and faced resistance from some scientists. However, Einstein himself remained confident in the validity of his theory and continued to work on its implications and applications throughout his career.
It's worth noting that Einstein did later develop a more comprehensive theory called general relativity, which incorporated gravity and provided a more complete framework for understanding the universe. However, this expansion of his work does not imply any dissatisfaction with his earlier theory of special relativity.