1. Learn to share. Whether it's time, food, a good story, appliances, your prior location to home, or simply how your day went, learn how to share it and not get freaked out when they ask. Yes, they really are bound to ask. Besides, you know you want them to :D
2. Always inform them of your whereabouts especially when you're going home late. Tactical interrogation by a protective mother and a more protective older brother is bound to occur lest you forget.
3. Noise is inevitable, especially with four children at home with different temperaments and artistic tastes. Live with it.
4. There are a myriad ways of expressing love, and they are not limited to mushyness and corny-ness.
5. Hugs from younger siblings are comforting.
6. Banter with younger siblings is fun and stress-relieving. Especially when long-running jokes are involved.
7. Be not afraid to burp, or cry, or lose your composure in front of them. (Truth be told, I am still working on this. Especially the crying part when watching movies. However, I have lost my composure countless times, especially when insects are involved.)
8. You are a part of the academic research process, as well as various other processes that involve certain degrees of responsibility. Be prepared to answer questions. Also, be prepared to teach them how to get to the achieved result.
9. It is never too late to learn the basics.
10. At the end of the day, no matter how FAIL you've been, family is still family. Even if you were born from another mother.
