A friend got his wallet stolen one time. He was lazy and hadn't used a good password or 2FA. However the same laziness meant all his coins were spread among many other wallets, which he eventually planned to gather all in one(the one that got stolen) so he only lost a part of his funds. Learn from others mistakes, don't store everything at the same place or at least use adequate security measures.

Also if you hold everything in one place and lose your private key/JSON file or whatever you use to log in, it's game over.