However there are many evidence in the relationship of Lysander and Hermia that supports the statement "the course of true love never did run smooth". In fact, Lysander himself quoted this statement to Hermia when Egeus was against their relationship. Egeus wants Hermia to marry Demetrius, but Hermia is in love with Lysander and she wants to marry him. Hermia was not willing to give up her true love and she didn't mind being brought to meet the Duke. She still insisted to the Duke that she would not marry Demetrius. This can be seen clearly when Hermia quotes ".whose unwished yoke my soul consents not to give sovereignty.,. Hermia is saying that she rejects this marriage and that she cannot call Demetrius my lord. This proves how true her love is towards Lysander as she had to go through all this trouble.
Other than that, Hermia's true love was also put to the test when Demetrius was crazily in love with her. All thorough the play, she was very faithful to Lysander as she kept rejecting Demetrius even thought at one part she thought that Lysander was dead. Hermia was also put to the test when Lysander liked Helena (which is due to the love potion). She refused to give up, as she couldn't believe it. She wanted Lysander back so badly that she went to the extent of fighting with Helena. This shows that she is willing to go through any trouble in order to get her love, Lysander back.
As for Demetrius and Helena, it is obvious that Helena is desperately in love with Demetrius since the beginning She goes through a lot of pain and receives insults in order to win Demetrius's heart. She doesn't mind being insulted by Demetrius as long as he accepts her as his lover. For an example, Helena quoted ".use me but as your spaniel, spurn me, strike me.". This shows that she is extremely in love with Demetrius that she is willing to be treated like a dog by him. She has gone to a stage of giving up her dignity and honour in the name of true love.