I don’t think it’s due to lack of fulfilment in early years – say childhood. I myself had a full childhood though I was bullied relentlessly on racial grounds. I don’t think bullying itself had a direct result but it did isolate me from society in a way I never had a chance of escaping. That did have an effect on my social skills and partly led to what happened later on in life.
You have a point about sexual desires I think. We (as a society) tend to be in direct opposition to ourselves biologically. For millions of years our species and the species we evolved from have had primary objectives of survival and procreation. For some reason we think we can change all that in just a few thousand years of culture. It’s akin to trying to derail a train going at 200 mph with just a pair of tweezers. Sure, it’ll have an effect but you’re not going to stop this thing.
So, humans have an insatiable hunger for sex at some point in their lives, but society doesn’t always allow them to respond to their biological needs. What happens then? Does biology just disappear? No, nature keeps upping the pressure until the person is desperate enough that they’ll do almost anything (and they do). What we need are cultural norms that allow us to satisfy our biological needs in ways that are healthy and do not harm others. Currently, we may think we have that, but statistics and observation prove otherwise.
As to your theory about wanting to catch up on lost opportunity, that is something that has happened to me, but only because of the extensive and prolonged bullying I experienced for decades due to where I was born (which I won’t divulge). There was nothing I could do to change where I was born so it became a social prison of which there was no hope of release and no crime committed to come to terms with it. Racial hatred is a horrible thing and causes long term damage. As I’ve said before, although this contributed to me missing out on developing a lot of social skills, I don’t attribute this to my sexuality.
True experimentation (like you get in a science lab) is only possible if you are free to experiment. Most sexual behaviour is not free so it’s not possible to experiment sexually without taking some quite big risks. I’ve lost count of the number of teachers, politicians, musicians, celebrities and people in TV and film who’s lost their jobs, homes, families and often their lives just because their sexual habits became public knowledge. Just last week another politician committed suicide after an allegation went public. We'll never hear if it was true now. This is the world we live in at the most civilised end.