It's a good idea to invest in bitcoins before buying clothes, but you should also remember to get stuff that makes you look good. Investing is good, and I also believe in not putting all my eggs in one basket. You can do different things that give you more in return. 
 
About you helping your friend who used his money for Christmas clothes and shoes; it's not bad to get that stuff too. But if you have the money, I will advise you to help him out. But give what you can easily let go of. 
It's not okay to judge people because we all have different priorities. 
Always feel happy to know you're helping people, and the rewards will come back for you. You can also advise them on how to make more money without lavishing it on things.