I’m the same. There are photos of me as a pre-teen that I remember my mum taking to prove to me that I wasn’t fat. I’m holding my hand/arm across my totally flat abdomen to hide it 
Once I hit 40 I decided I didn’t owe anyone a nice view, that I should wear whatever I felt happy in. And for me, in the sun on holiday, that means tanning as much of my wobbly, cellulite dimpled, stretch mark riddled, fucking fabulous miraculous body as possible!