I was learning with my chevruta about how one should not keep Chumrahs that one's Rabbi or community doesn’t keep. I can’t remember where I learnt it. Would anyone have a reference?
In Betzah 36b, a bad thing happens to Abaye, and he thinks this is punishment for "having gone against the words of my master, Rabba".
How is this relevant? Jews who observe a rule most other Jews do not observe fall into two categories:
(1) Those who believe their rule is halacha and the others are breaking halacha.
(2) Those who believe their rule is not halacha. but that there is value in following some extra-halachic rules.
If their rabbi does NOT follow that same rule, then one of two things:
(1) They disagree with their rabbi on halacha. (Which is not allowed.)
(2) They disagree with their rabbi on the value of some extra-halachic rules. (Which may or may not be allowed.)
Therefore, whether what they are doing is right or wrong depends on what they believe they are doing.
As for the definition of the word "chumrah", some say it's (1) and others say it's (2). This article distinguishes between chumrot based on halacha and chumrot required by halacha, implying that the word just means "stringency".