No, you are not alone by having situation like this.
Life is tricky thing it does things unexpectedly and unimaginable.
Let me tell you about my batch scenario in college.
In our batch :
Person of age 17 during admission – approx 20
Person having age of 18 – 20- approx 210
Person having age more than 20 – approx 20
In our batch there is girl though I won’t reveal her name, is eldest in our batch.
She was 22 yr old at the time of admission.
Does she get depressed in college by age effect?
No, she is totally free, mischievous, intelligent, sexy (like really sexy) and hot too.