Collecting stamps was my favourite hobby as a schoolboy , closely followed by collecting matchboxes and collecting coins , in that order . 
A particular aspect of stamp collection was a direct outcome of effort made - the FIRST DAY COVER. The General Post Office at Calcutta had a philatelic bureau that used to have first day covers - ( a first day cover has a stamp on the official envelope, stamped on the day of release)
Attached in the picture are some of my first day covers - they are not just first day covers - behind each is the familiar story of my mother rushing with me and my sister to the GPO ( which closed at 5 PM). For context , school got over at 3.10PM, and we reached home at 3.45 PM. And then, we would make a beeline for the bus to GPO,  a one hour journey from home. 
No matter what the first day cover - Indira Gandhi, Asian Development Bank, 150th anniversary of the postage stamp, Ho Chi Minh - it not only had the postmark - it had the indelible stamp of my mother's love on it !