I grow up in national school, attended countless of Hari Raya, Deepavali, Wesak, CNY and other festival like Raya Korban, Ponggal and Thaipusam.

Still don't make me any bit of religious at all.

No puasa but I have participated in a few cow slaughtering, during school time and during adult including few years ago slaughter of camel. During the agama class, me and a few non-muslim stayed at the back of the class (school don't have enough non-muslim student to have POL class) until we can hafal alfatihah, which is the first thing they do during agama class.

I also have supported my friends who are taking the kavadi in batu caves, and have to endure the climb up the cave.

Yes you are right. Celebrate! No one is asking to join in the prayers. During the prayers, all you need to do is keep silence and be respectful. Niat itu penting.