As a kid, I was always small and never as strong as my peers, but what set me apart was that I had no sense of smell. At school, if somebody farted in class, I would be the only person who remained oblivious. Consequently, I always got the blame.

Knowing something wasn’t right, I told my mother, but she was working her guts out single-handedly to support three children. Because of my size, I was bullied almost daily. I went to a weight-training class and I could barely lift more than the bar. I enjoyed baseball and football, but lacked the competitive instinct that seemed to come naturally to other boys.

Eventually, my size caused enough concern for a doctor to prescribe shots, which I think contained a growth hormone. I started to grow a bit, so my problem wasn’t investigated further, but I still looked much younger than I was. My teenage years were rough. While boys my age grew facial hair, I still looked prepubescent; I became an expert at avoiding physical education and the dreaded communal showers. The pitch of my voice stayed the same, too. Although I had friends of both sexes, and crushes, I never had a girlfriend.

My delayed puberty even got me into trouble with the law. When I started driving at 16, I was pulled over repeatedly, until every cop in my small Utah town had seen my licence and no longer thought I was a 12-year-old who had stolen his dad’s truck.

Throughout all this, it was assumed I was just a late bloomer. But the longer it went on, the more my confidence suffered. I felt robbed of something I couldn’t articulate. My friends were driven by urges I didn’t understand, and my longing for a girlfriend was, I think, less a sexual impulse than a need to be fully accepted by someone.

In the end, my diagnosis came thanks to a packet of coffee. I’m a Mormon and at 19 I decided I was ready to complete two years as a missionary in Dallas. Before doing so, I had to undergo medical checks. The first doctor who examined me saw straight away that something was wrong: my testicles hadn’t descended; I had no body hair; I hadn’t gone through puberty at all. But this endocrinologist knew something the small-town doctors I had seen previously didn’t. It was she who held the coffee under my nose and asked: “What do you smell?” Of course, the answer was: “Nothing.” My inability to smell was a symptom of a rare genetic condition called Kallmann syndrome, which meant my body failed to produce the hormones that trigger sexual development. This revelation was like finding the missing puzzle piece.

The treatment led to quite a dark time, though. I underwent hormone replacement therapy to force me through puberty and experienced in one year changes that should have taken four. At the start of that period, I was 5ft tall; before the end, I had grown 8in. As the hormones raged through me, I felt constantly angry. I would come home from work and hide in my room, lashing out at anyone who talked to me. I have to say, my mother was a saint.

As the treatment continued, I started to feel a lot better. Although I still looked younger than my years, I could grow facial hair, and people viewed me as the adult I was. I no longer felt as if something was broken inside me; I had newfound confidence.

Two years later, I met Jessica at college; at 23, I finally had a girlfriend. It took me a while to broach the subject of my syndrome – most people with the condition are infertile and I feared it might be a deal-breaker. We have now been married for 15 years and, after treatment to increase my sperm count, we are expecting a child by IVF.

It has been a long, emotionally draining and expensive process. I’m 38 now, but I look as if I’m still in my 20s. Thanks to the doctor who diagnosed me, I was able to get a good portion of my medication covered by health insurance, but we had to pay for our fertility treatment. I feel terrible for the people with Kallmann syndrome who can’t afford treatment, because I know what a difference it has made to me.

I wouldn’t change anything, though. Those years when I wondered if I would always feel like an outsider made me kinder and more resilient. I look back and think: “You know what? I was a pretty cool kid.”

• As told to Chris Broughton

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