… 以来 (ever since)

Counting from that day

• Time / Event + since (a previous event)以来yǐ lái = "ever since / over the period since".
• graduation毕业bì yèsince (a previous event)以来yǐ lái = "since graduating"; 三年sān niánsince (a previous event)以来yǐ lái = "over the past three years".
• It opens a stretch of time running up to now.

Time / Event + since (a previous event)以来yǐ lái，…

• since (a previous event)以来yǐ lái marks the span from a past start until the present.

graduation毕业bì yèsince以来yǐ lái，I我wǒalways一直yì zhívery很hěnbusy忙máng。

• graduation毕业bì yèsince (a previous event)以来yǐ lái，I / me我wǒall along一直yì zhívery很hěnbusy忙máng = "since graduating, I've been busy."

Recap

Read the full reference: HSK 5 grammar — Nouns.