Alice encounters many puzzles that apparently have no obvious solutions. She feels that there would be a solution to troubles she encounters, however they constantly frustrate her capacity to find out wonderland. In every case, the challenges and riddles appear to her have no answer or solution. She learns that it is almost impossible for her to find meaning and logic in such troublesome situations. Carroll in fact, conveys his idea about such ways, which resist interpretation and frustrate expectations, even when the troubles and problems seem solvable. so, yes this is one of the main themes of the story.
Theme of “Life is like a Meaningless Puzzle” in Alice’s Adventures in Wonderland