In Vajrayana transmission, you learn how to give up everything totally, how to completely surrender your body, speech, and mind. You learn how to relate with the teacher, and you give in thoroughly and utterly.
Giving in or surrendering means not holding back anything that you cherish: any personal pride, personal anger, personal jealousy, personal passion, personal ignorance or delusion.
Once you let go of all that , you begin to feel a sense of relief and joy.