COME ALONG (1), COME BACK (4)

come along = appear

examples:

• She always wanted to live abroad, so when the opportunity came along, she took it.
• When the chance comes along, I 'll ask my boss for a raise.
• We didn't intend to sell the house, but a very good offer came along and we changed our mind.
• I was sitting alone on a bench in the park, when an old friend came along.
• Jenny is so lively and funny! We always have a good laugh when she comes along.
• Luckily, a car came along and we took Ben to hospital right away.

 come back (to somebody) = remember 
examples:

• I had forgotten his name but when I saw him it came back to me.
• I had a nightmare about my mother. It came back to me when she called me this morning.
• I tried to remember what it was that I wanted to tell Jim but it never came back to me. It can't have been important.
• She 's a lawyer at a firm called ... oh, I don't remember it. It will come back to me later.
• She couldn't remember anything after the accident. Everything started to come back slowly a few days later.
• I was afraid I wouldn't remember anything for the test but when I read the questions, it all came back.