[chownie]

I grew up in a clean household, no shoes indoors, fastidious mother wiping down every surface, also allergy free.

So are all of my siblings though, so there might be more of a genetic component to this.

[barrenko]

I grew up on almost a farm smack next to a nature park, was very outdoorsy kid and have all kinds of allergies ever since puberty onset.

[falsaberN1]

Yeah I don't think allergies depend on external factors that much. My mother and I have pretty equivalent childhoods even down to same locations and she's wrecked with allergies and I have none, yet my health is worse overall (despite me having a healthier lifestyle).

While I believe some exposure helps build resistance ultimately your overall health will be influenced by stuff beyond your control AND your lifestyle/activities combined.