@Blondeshavemorefun
Why batshit... no need to change my number
I was with cellnet I think , then o2 for decades and swapped to lebara last year. And kept number
@DobbyTheHouseElk
Why is it batshit?
OK, it's batshit (to me) because I don't know a single soul in real life, who has the same mobile phone number that they've had since they had their first mobile phone - in the mid to late 1990s, as many posters on this thread say they have.
I even know a number of businesses who have changed numbers in the past 30 years, but it seems a LOT of Mumsnetters have had the same mobile phone number for 3 decades. (And it's the very first number they ever had.)
Some say since 1995. I didn't even know anyone with a mobile phone in 1995! I had my 2 DC around mid-late 1990s and not one single woman in the hospital (in the 10 days I was there) had a mobile phone. Or any of their visitors, or the staff... When I was at work in the mid-late 1990s, no-one at work had one. Also, none of my friends, aquaintances, or neighbours, or family members. It was 2001 before DH and I got one. Many people had one by 2003-2004. Certainly not 1995-1996.
Parallel world of Mumsnet strikes again. 
I am NOT saying people on here are lying, I just don't know anyone - in real life - who has had the same mobile phone number for 30 years, (and still have the first phone number they had.) As I said earlier, maybe 15-16 years yes, but no-one I know has the same mobile phone number they had in the mid 1990s. (And as I said, I didn't even know anyone who had a mobile phone then!