[annabellish]

Yes, but also no. The trick here is that if you're paying for your £1,000,000 space rocket by transfering the bitcoins from one address, it's a small transaction.

If you're paying for your £3 coffee by transfering small amounts from many addresses, it's a big transaction.

Address fragmentation happens when your coins are distributed across many addresses, and can be caused by things like spending coins, because all transactions actually spend everything at an address and just route the "change" elsewhere. Buy two cups of coffee too close to each other and your next transaction is going to cost twice as much in fees, whoops!