Whether you need to change your mobile phone when you go to college is not necessarily your problem. Changing mobile phones is usually determined by personal needs or technical limitations. Here are some situations that may cause you to change your phone:

1. The function of the old mobile phone is insufficient: If your old mobile phone can't meet your needs during college, such as slow processing speed, insufficient storage space and poor endurance, then changing the mobile phone is a reasonable choice to improve the experience.

2. Academic needs: During your college years, you may need to use some specific applications, online education platforms or conduct distance learning. If your old mobile phone does not support these functions, then changing your mobile phone is a decision made to meet your academic needs.

3. Maintenance difficulty: If your old mobile phone has serious faults or needs frequent maintenance, and the maintenance cost is too high or the maintenance time is too long, this may prompt you to choose to replace it.

4. Personal preference: Some people like to try new mobile phone models or brands. For them, changing their mobile phones is a fun and curious experience.

In short, whether you need to change your mobile phone depends on your specific situation and needs, not entirely your problem. It is important to make reasonable decisions according to your own needs and economic situation.