I'm guilty too. As a teenager i spent most of my time egg collecting. It was common place at the time, either that or buy an air rifle and shoot them! I must stress I NEVER SHOT birds. I could never bring myself to do that. The thing was at that time there were not many birdwatchers not that i was of aware of anyway, we're talking about the early seventies here, around 73-74 and i was 12. All my mates collected eggs and there was competition not so much for rare eggs more for the number. If you had six Blackbird eggs, five Hedge Sparrow(as we called them then) and six Song thrush eggs, you had a good collection. We used to "blow" the eggs by pricking each end with a pin and blowing the contents out then set them in a nice display box filled with sawdust. If we found a nest we would "raid" it 2 or 3 times until the birds stopped laying. This was when my 12 year old concience started to kick in and i stopped telling my mates where the nest's were. I would still go "nesting" but not to get the eggs but to watch the birds which was easy because i knew loads of nest sites, far more than i know today. I think the final straw came when 2 so called mates at the time had obviously followed me to a Bullfinch nest, only to later present me with a "cake from the local cake shop" which contained Bullfinch nest complete with clutch of 4 eggs!
I am ashamed of what i did but if i hadn't have done it i wouldn't be the bird watcher i am today and i think this is true of a lot of people of that era. Some grew out of egg collecting and went into the next thing that young people were doing, others, like myself discovered the wonder of birds.
Let us not forget, at the time people didn't think they where doing anything wrong, and according to the law, we weren't. You could drink and drive and not wear seat belts etc... but it did introduce a lot of young people to wildlife.