Is it just me?

I always wash new sheets, towels and clothes before using.
They have chemicals on them and I don't want those on my skin.

Absolutely not!

For some strange reason I feel the need to wash new duvet covers, but not bottom sheets. Probably a bit of OCD there. Definitely towels though!

I've never bothered to prewash new bedlinen. Cotton, and especially non-iron cotton, is highly treated with chemicals anyway, to turn them into fabric. Even organic cotton uses chemicals to turn it into fabric.

I wash everything new, bed linen, towels, tea towels, throws,
Underwear and clothes

I never wash anything new - and pinkquartz, when you wash em, I hate to put this to you, the soap you use to wash and condition em? Yup, full of chemicals, sorry.

Lisaliu actually the washing liquid I use is not full of chemicals!
I use a one that is harmless to health and ditto fabric conditioner.
Please Do not tell imply that I am stupid and unknowing regarding chemicals. We are all made up of chemicals....the thing is some are toxic. An issue that is becoming more relevant all the time.
Also my skin reacts to new textiles if it's not washed.
I have a condition known as Multiple Chemical Sensitivity , I react and become very ill if exposed to many man made chemicals. I have dysfunctional immune system and after being exposed to certain chemicals I am now over sensitive.
But what I react to are exactly the toxins now being shown to cause health problems.

I don't care if other people don't wash new bed linen but I wanted to back up the OP and add my bit. I can smell new clothing.....and some of it smells really bad btw.

No, life is too short!

Agree - they are new - why should I wash them if they have been put clean into a see through cover.

I don’t wash anything new unless it smells chemically. I don’t like the smell of any of the softeners either. They smell false. But I do put dried lavender in the sheets drawer.

I wash new sheets , but I never use conditioner , I am super sensitive to scents and I like my towels rough rather than slimy

Yes I always wash new bedding, duvet covers etc, pyjamas knickers etc.

My dd doesnt't shes a "straight from the packet girl lol"

I have never thought about washing new stuff. Can't see the point.

I couldn't bear to put anything near my skin that hadn't been washed. It's the thought of the warehouses where they are stored, or the bales of material are stored before they are made up. There are rats and all sorts of insects in those warehouses and then they have been through several hands and possibly shipped from tropical countries.

I once gave one of my sons a few pairs of pants as a stocking filler, and despite my advice, he wore them without washing them first and got a very serious urinary infection.

I always wash new textiles because of the fumes.

No wash when they've been on not before!

Size is a starch which is added to fabrics during manufacture to change the absorption and wear characteristics. With some textiles it acts as a glaze to put a sheen on the fabric. It's usually added to either the warp or the weft during manufacture and is called sizing. It's done because threads are less likely to snap in the manufacturing process if they've been sized.

You can feel it on new sheets and towels and some cotton garments like new shirts.

I wash it out before first use.

I wash bedding, towels etc for the same reason as Ginny42 I prefer the softer feel of the material after washing.
I would have thought it quite unlikely your son caught his UTI from unwashed new pants JackyB

It's sad to think that the new bedding has to have its chemicals washed off before use.
I probably wouldn't but they do have a strange new smell which is not very nice. I like the smell of sun on the washing when it's dried on the line.
I loathe the row in the supermarket of washing powders and conditioners. I walk briskly past and always buy ecover or other chemical free powder

Yes- they have all sorts of 'finishing' in them during manufacture. Always wash them before using in case you get an allergic reaction.