1. Academic pressure: College courses are usually more in-depth and complicated than high schools, requiring more time and energy to learn and understand. At the same time, a lot of homework, papers and exams need to be completed in college life, which will bring great pressure to students.

2. Time management: College students need to manage their own time, including attending classes, studying, socializing and taking part-time jobs. For some students who do not have good time management skills, it is easy to feel tired and stressed.

3. Social pressure: In college life, students need to establish contact with people from different backgrounds and cultures. This may bring some difficulties and pressures to some introverted or unsociable students.

4. Economic pressure: College life needs to pay tuition, accommodation and living expenses. For some students with poor family economic conditions, economic pressure may be one of the reasons why they feel tired.

5. Psychological stress: In college life, students need to face various challenges and difficulties, such as adapting to the new environment, dealing with interpersonal relationships, and finding career directions. All these will bring some psychological pressure to students, which will lead them to feel tired and anxious.

In a word, college life makes people feel tired because this stage involves many new challenges and responsibilities, and students need to pay more efforts and energy to deal with them. At the same time, everyone's personality, ability and experience are different, so the reasons for feeling tired will be different for different students.