"كان حلمي دائما الفوز بالبطولات الأربع الكبرى"

Simplified Meaning:

The person is talking about a big goal they've always wanted to achieve in tennis. Winning a Grand Slam means winning all four major tennis tournaments in a single year. This is a very difficult and rare feat because you have to be the best in the world. Think of it like training very hard to get first place in four different races throughout the year, and doing it successfully shows you are on top of your game. For example, someone who loves running might dream of winning the Boston Marathon, the New York City Marathon, the London Marathon, and the Tokyo Marathon in the same year. Achieving this dream would take a lot of practice, determination, and skill. Similarly, in everyday life, people might have dreams like finishing school with top grades or becoming an expert in their job. To reach these dreams, they need to work hard, stay focused, and not give up, just like the person aiming for the Grand Slam in tennis.