I'm allergic to some insect bites but I never see what has bitten me so I don't know which ones. Its not a full on anaphylactic reaction thank goodness. The worst reaction I've had was when I was on holiday in Sorrento. I had a raised red itchy circle of skin 3 inches across around a bite despite using antihistamine cream. My doctor advised me to take antihistamine tablets instead.
I've also got a few food intolerances which have developed as I've got older. Its not a proper allergy but they do make me ill the next day. Sometimes its OK if I only eat a very small amount, others I daren't eat at all. Avoiding those foods can be difficult, for example chilli is in many tasty sounding menu options in restaurants. I'll read through and think ooh that sounds nice then get disappointed when I get to chilli in the ingredients list.
Growing up I was very allergic to grass, got hives and trouble breathing just from going past a mowed lawn. Now, nothing. Cut grass doesn't bother me anymore, dunno why, but I grew out of it.