Strange that he will recover and be able to use his hands back, it can be seen (41:28 – 42:04)
The Ancient One leaves Dr. Strange alone only wanted to prove that he could still return to Kamar-Taj using his sling ring and the strength of his hand, not long afterwards, Dr. Strange finally managed to rely on the strength of his hand and returned to Kamar-Taj despite his hand being disabled. This proves that The Ancient One always educates Dr. Strange in various ways. The third content that shows The Ancient One is a static character is when The Ancient One felt that the sorcery skills of Dr. Strange is advancing quickly, and she wants to show him a new things that can be learned to next level. It can be seen from conversation (44:55 - 45:19) below:
Because The Ancient One felt Dr. Strange is rising very rapidly, so it's time to tell him something about the dimension of the mirror. The dimension of the mirror is a dimension where we are in various places but undetected and the real world is unaffected by what is happening here. This dimension is used to practice and observe. From that we conclude that, The Ancient One always wanted to teach something that can make Dr. Strange trained his hands to