Wear what you like! This whole dressing your age bollocks is just that.... bollocks.
I'm 47 and wear Superdry. I also wear Levi, Ben Sherman, Hilfiger, Armani and Ralph Lauren, all of which have logos of different shapes and sizes on the outside.
Sorry I'm not ready for Gant and M&S yet, they're for 'old men'.
Just be you and be happy. Remember, always be you. Unless you can be Batman then always be Batman.
Happy shopping.