Disabling converting values like "1-1" to dates during copy&paste of multiple values?

Is there any way to disable the automatic conversion of values like "1-1", "6-15", "8-3" to dates like 1-Jan, 15-Jun, and 3-Aug?

I know typing an apostrophe prefix stores the cell value as e.g. '1-1 but displays as 1-1. But I'd like to copy large tables where the cells are a mix of normal text values (e.g. "apple"), number values, and the date-looking values that I'd like displayed as text. So some cells would need the apostrophe prefix and others wouldn't. I don't know what the appropriate solution is in this case.

Also, if I copy&paste a value like '6-15 (e.g. from notepad, with the apostrophe included in the copying), it actually displays for me as '6-15 - with the apostrophe displayed. Why is this?

Do a CTRL + A - which selects all your cells, right click on mouse and choose, "Format Cells." Then on the "Number" tab, click on "Text." Click OK - and you can input your numbers as text.