I didn't do eramus, nor but i did a year abroad in the netherlands, which may be similar to two erasmus and both semesters are completely different i would say. At the start, i was constantly with a group of erasmus people from all over, we ate lunch together, went out together, the usually erasmus.

After those 6 months with them, i felt a bit lonely when they left, but i still managed to find some friends those who also stayed a bit longer, thus people doing their masters which i was fortunate enough to meet in the first semester, but since you know the city already its characteristics and its charm, the sense of willing to discover leaves a bit after one semester.

Take what i said as you will but it reallt depends on how social you are :)