Difficulty with erections is not that common and doesn't happen to "real" men right?

Wrong. Happens to lots of real men...Can be sign of big medical problems....What is a real man....? Not really a medical term.....Really.
Happens occasionally. A good erection is greatly influenced by emotions. In a younger man, without age-related erection problems or hormonal imbalances, a poor erection can be due to stress (stress at home, at work, in the relationship, etc.), due to other distractions (a toothache, a tummy ache, etc.), due to worries (worries about getting a woman pregnant, catching an std, his "other girlfriend finding out", etc.).