Emor. Why Count the Omer?

We are currently in the heart of the period known as the Omer, the 49 day-count that links Pesach and Shavuot, and the source of this mitzva may be found in our Parsha. Each day we signify “Today is X days to the Omer,” detailing weeks and days.
Discuss these questions
Why do we count from Pesach to Shavuot? We don’t count to Pesach, or to Rosh Hashanna! Why count here?
When we count days, it is usually to a special event; a birthday,a trip abroad, an exam towards which one might have to plan and prepare.
What are we preparing for in the lead-up to Shavuot?
Most people suggest that this count is a linkage between the Exodus and Matan Torah, the Revelation at Sinai and the giving of the Torah.
“It may be compared to a prisoner who receives a message: “On such and such a day, the king will release you, and fifty days later, he will give you his daughter’s hand in marriage.” He responds, “Let’s see me get out of jail first!” After the king released him, he says: “Now that the first promise has been kept, certainly the second will also be realised.” And so, he began to count fifty days, until the king had him marry his daughter as promised. Similarly, when God spoke to Moses [at the burning bush,] he said: “When you take the nation out of Egypt, you will worship God at this Mountain [Sinai]” (Ex 3:12). They responded: We cannot believe that we will be redeemed, we ca